Dean's second single is much different than the first.
"Going Well" is, as the name would suggest, a song about acknowledging all the good in his life. "How?" is a sadder, slower song that's really a hit or miss. Slow songs rarely do well on the radio. There's a reason Taylor Swift releases the "ME!'s and "Shake It Off"s first, and the "Delicate"s and "Lovers" later, and the "Dear John"s and "I Almost Do"s never make it past the album. People don't want sad. They want catchy.
On the other hand, "How?" is sad because it's about Jo. It's the song he told Jody Mills he had been thinking of adding to the album at the last minute. It's the one he told the paparazzi is about his "feelings on being stabbed in the back." He won't admit it out loud, of course, just like he won't admit that Castiel stole his girlfriend. He won't say it, but he'll allude to it with just enough passive-aggressive comments that it's unmistakably about the breakup.
He's not sure how he expects people to feel about it. Slow songs are a dime a dozen. People would usually rather listen to things with unique sounds, not just Dean's wonderful guitar in the background. At the same time, though, people are going to be very interested when they hear Dean wrote a song about his relationship ending. Sure, he didn't technically write it — he wrote the melody, but he can't take much credit for the lyrics — but the general public doesn't need to know that. If all goes well, they'll hear about it and need to check it out, if only to tell him that he needs to shut up and move on.
The general public aren't the only ones checking it out, though.
Castiel: I like your new song.
Dean: Thanks :)
That's how he replies to everyone that texts him that — and by "everyone," he means at least 25 people after every release. It gets a little exasperating.
Castiel opts to keep the conversation going, which most people don't bother to do.
Castiel: Thank you for not making me look like a piece of shit in it.
Dean: Well you deserved a break from it lol
He doesn't point out that he didn't write the lyrics. It's common knowledge that a lot of musicians don't write as much as they let on — unless they have a large collection of songs with themselves set as the sole writer, it's a safe assumption that their team carries them through it — but outside the industry, people don't tend to know. He doesn't want to be the one to tell Castiel that he's not the lyrical mastermind people like to think he is. He got this gig out of pure luck, not talent.
Castiel: Would it be too much to ask for you to perform it acoustically eventually?
Dean: It practically is acoustic tho
Castiel: Yes but performances always sound better than studio versions.
Dean chuckles. If he had a dollar for every time someone said that to him, he could probably buy out all of Disney World. He doesn't agree, of course — the studio version is specifically edited to sound the best it can — but it's funny that so many people think so.
Dean: Well idk if you keep up with my social media but I'm not scheduled for an SNL performance tomorrow night for no reason ;)
Castiel: I can't wait!
Dean smiles. He hadn't expected to find a fan in Castiel, but he's glad he did. He may not have ever texted Meg first, but he does text Dean first. Maybe he's not the lonely guy Meg thought he was after all.