Therapy game is pretty good. I don't quite remember if its exactly what you're looking for or not but one of the characters helps the other through their trauma.
“Incidentally living together” I didn’t finish it but I remembered it being good
The only one I know with that exact theme is Incidentally Living Together.
These other ones deal with other disorders but they might be similar enough to what you're looking for:
The Pizza Delivery Man and the Golden Palace's mc is a man with severe social anxiety (might've been agoraphobia, I don't remember if they ever explicitly said what disorder it was).
Ten Count's mc has mysophobia. I didn't really like this one but I know a lot of other ppl really enjoyed it.
Thank you so much!
Anyone know of any manhwas where one character has [signs of] depression/an eating disorder/suicidal thoughts and another character helps them through it? Pref colored :)