Okay
Listen
Bucky is not going to be madly in love with your OC in the first 3 chapters after they just met. And even if he is he's not going to be shouting it from the rooftops and acting like a random NON TORTURED MAN.
James FUCKING BARNES DID NOT GET BETTER AND UNCONDITIONED FROM HIS HYDRA WAYS OVERNIGHT.
I mean Steve damn Rogers had maximum difficulty getting him somewhat better. But your OC whom good ole James has known for a week probably is not going to "fix" him immediately.
What I'm trying to say is that if a Bucky fic is anything , if it's going to be anywhere near accurate, it's going to be a slow burn