Steve wasn't about to let Bucky go back to hurting himself, and so he didn't let that wrist go. It didn't mean he didn't keep Bucky close with his other arm, though, even as he kept sobbing - although he was starting to get worried at the sound of those sobs. And then -

"Bucky - Bucky, hey," Steve said urgently. Bucky might not want to look, but Steve had, and he didn't like what he saw. "Hey, look at me. Come on. Take a deep breath. With me."

This was a panic attack, not an asthma attack. But Steve had had plenty of the latter, and he was hoping that maybe the same strategies would work. Because he needed to get Bucky some help, but he needed Bucky to calm down, first. "It's okay. Come on, you're okay."