(Authors note: had to spice it up. Trigger warning for self harm, eating disorders, flash backs and annoying ass Deku. JUST READ IT.)
Ever since the whole Deku thing happened, he realised he must be making some sort of mistake. He had already had two people question his welfare, and to be honest, he didn't want the deal with that. He really fucking hates it when people look down on him.
To compensate for that, during class, if he felt himself drifting off, he would dig his fingers into his thighs to try to bring himself down to earth. Instead of trying to abolish his intrusive thoughts, he welcomed them with open arms, to use them as punishments against himself. In a hope that it would help lose weight, he restricted his diet to one meal a day (variating in portions based on how he feels that day). In desperate attempts to gain muscle mass, he would push himself past limits, to the point where he was never free of aching muscles, it wasn't healthy at all. Repetitively, he would push things onto himself that were completely unnecessary (and probably not good for him due to his mental state) like forcing an extra couple hours of studying, when all he wanted to do was pass out and never wake up again. In his mind, this was self-discipline, but in reality, it was nothing but damaging to him.
People like Deku, Kirishima and his mother were all trying to ask about his well-being still, so even getting back into his work out frensies and focusing in class more wasn't enough? He, once again, had to switch a few more things up.
He tried to start more arguments, like how he usually was, and tried to be louder and more easily agitated during class.
It took a good 4 weeks, but he got the nerd and people alike to stop pestering him about shit they had no business in. They were slowly, but surely getting used to Bakugou being 'himself' again. But something still bugged Deku about the way Kachan's eye-bags were so prominent, and the way his face looked slightly thinner with each passing week. But Izuku tried not to worry himself too much.
Although Bakugou hated to admit it, sometimes he felt like he was going insane with the need to tell someone about everything. He was a very honest person, and something felt so wrong about not being truthful in the moments when he lies to people asking if he is ok. Well, he didn't lie when he said it wasn't anyone's business, and they don't need to know, but in this case, when he tries to keep the same mindset, he just feels so isolated and alone.
So, desperate for those feelings to leave, he reverted back to his middle school ways...
By that, he means that he relapsed with self-harm. He could remember the string of events that occurred during middle school, so well, that every time he pressed a sweaty palm against his thigh, or cracked open an 'innocent' sharpener, he had small flash backs of what happened.
(flash back timeeeeee)
A couple months before the UA entrance exam, Bakugou could really feel the weight of everything that was going to go down. He was going to have to prove himself to top notch heroes, and teachers that have taught generations of heroes. It wasn't going to be easy, but he knew he could do it. Despite being so big headed about it, he couldn't help but feel a sense of doubt linger, and that, once small pinch of doubt, turned into a big whirlpool of negative feelings about it. He hated feeling that way, not just because it felt bad, but it made him feel weak. So in a desperate attempt to relive some sort of stress and anxiety, he skimmed google for days and weeks, trying to find a solution.
He tried all of the following:
More exercise.
Bathing.
Scented candles.
Reading.
Drawing.
Fucking everything, until he came by a questionable page promoting self-harm. Only being in middle school, he knew what it was, but didn't at the same time. Desperate to rid himself of feeling the way he did, he tried it, just a simple scratch during class if he got an answer wrong. And sometimes pinching his arms when he felt kind of stressed. The sharp pangs of pain took his attention off every emotion he wasn't able to comprehend, and made his mind zone in on the pain. It was peaceful. Until, it became an addiction, and he was too used to small scratching and pinching. He started to delve further, and use his quirk to burn his skin and steal sharpeners from school to use for proper cutting.
He didn't understand any of it. He was too caught up in the freedom, that he didn't know what he was being freed from. It was very problematic, and it wasn't going to change, until...
"Alright boys! Go get changed for your swimming lesson!" The old musty gym teacher yelled to the big huddle of sweaty teen boys groaning and complaining.
"Can't we do something else!" A kid shouted from the back of the huddle.
Anxiety building in his stomach and making his belly do back flips, it told him to leave right away, or else everyone would find out about IT, and think he is disgusting, so in a frensy, he yelled, "I can't fucking do it teach!"
The teacher, already being used to his potty mouth by then, rolled his eyes and humiliated Katsuki in front of 30 other boys, "What? Can the all-powerful Bakugou not swim?"
The class all burst out laughing, and Bakugou's brows furrowed down, his face contorting into that of anger.
"GRRRRR! I HAVE A FUCKING VERRUCA BITCH!!! UNLESS YOU WANT THE WHOLE CLASS TO GET ONE, I SUGGEST YOU LET ME LEAVE THE FUCK NOW!"
The gym teachers face turned red with fury, and he pointed a hairy, fat finger at the door, "LEAVE MY LESSON NOW, BAKUGOU. I WILL NOT STAND FOR THIS. THE HEAD TEACHER WILL BE HEARING ABOUT THIS ATROCIOUS BEHAVIOUR!!"
Anger still written on Katsuki's features, he stormed out and tried to ignore the snarky remark the teacher muttered, "You can get that 'verruca' checked out while you're at it."
Anxiety trying to crawl in his skin at the notion that the teacher didn't believe his verruca story, he marched over to the year leader and told her what had happened. He'd always liked her because she never screamed at him like the other teachers and his mother would, so when he was put into isolation the rest of the school day, he asked to be put in her office for the isolation.
When school let out, he swung his backpack over his shoulder and stormed out, just being his usual self, until he saw a certain green haired annoying twerp at the gate. Wanting nothing more than for everyone to disappear, he pretended not to hear the cry of 'Kachan!' and just kept walking.
Deku however, must have been desperate, as he reached out his hand, and grabbed Katsuki's forearm. Not anticipating it, Bakugou winced and pulled his arm away. Turning around, he grabbed Deku by his blazer and dragged him out of school grounds so he could cuss him out privately.
"What the fuck do you want Deku?! Ugh, so annoying!"
Slightly hunching into himself, Deku mumbled something unintelligible.
"Speak the fuck up Deku or I'm fucking off out of here."
Staring and his shoes with doe eyes, he spoke up slightly, enough for Bakugou to hear, "U-umm... I was worrying about you because of the swimming thing..."
Anger bubbling at even the thought of Deku daring to look down on him, he yelled, "I don't need your fucking pity! I'm fucking fine, bitch!"
Deku knew he couldn't leave the situation at that, he had noticed Kachan seemed off lately, and although Kachan wanted nothing to do with him, his hero complex wouldn't let him accept that answer.
"If your fine, Kachan, then let me see your hurt arm."
Almost grating his teeth at the sound of Deku being confident, he scrunched up his eyes and prepared a big stream of cuss words to spit at the green haired boy. In the small moment that Kachan had let his guard down, Deku reached for his arm, and used the muscles he had been building up with Allmight to try and hold Kachan's other hand down as he pushed the sleeve up. He wasn't ready for what he witnessed.
His eyes widening in horror, Deku let Katsuki's tense hand fall out of his grasp. The sleeve still being pulled back, he just gawked at the scratches, especially the big thick ones with dark red scabs. But the thing that clarified the fact the wounds were self-inflicted, were the big burn marks, splotched around randomly on his arm.
Deku felt tears build up behind his eyes, and he stared at the way Bakugou tried to hide his hand behind his torso and kept averting his gaze. Then it was true, Kachan, the same Kachan Deku had known for his whole childhood had felt the need to hurt himself, and went through with it. Deku had tried, his whole life, to take the brunt of Kachan's anger to protect others, in the end, he couldn't save Kachan from himself. Sobbing on his knees, he heard Kachan shift uncomfortably in front of him, and sobbed even harder.
"Nerd... Don't fucking cry... You're being annoying!"
"B-but b b but! I couldn't help Kachan! I was supposed to be your outlet! But I failed! At even the simplest tasks... I didn't want you to hurt anybody... but now I realise I needed to stop you from hurting yourself! Please forgive me!!"
He was fully on his knees crying and apologising non-stop, preventing Katsuki from really being able to say anything.
"NERD!" Deku snapped his head up at looked at Kachan through teary does shaped eyes, "It's not your fucking job to take care of my temper tantrums, or me for that matter. I did this to myself to relieve stress, ok? Not to put my stress on others shoulders, so just don't tell anyone, and I'll find a different way to relieve stress, ok?"
Still sniffling, but shell-shocked at the softer and more comforting tone Kachan was using, he nodded his head, and added to the deal, "O-ok, b-but if y-ou do it again. I-I'm going to tell your parents, and our teacher!"
After parting their ways that day, if Bakugou cried at the fact that Deku still cared about, him after everything he had done to the kid, he didn't.
(flash back over)
Cringing at the memory, Katsuki vowed never to let Deku know about it again, he didn't want his parents to find out, and he didn't want Deku to tell Aizawa, that would be the absolute worst. So, after blocking Deku's number, he slept for a good 10 hours.