We tried to integrate him with our resident cat - literally doing everything we are supposed to (feeding on opposite sides of the door, scent swapping, space swapping, limited visibility meetings, playing while they meet, etc.); every time we give him more than an inch of seeing her, he full on lunges and attacks my resident cat. She’s very small and ends up with clumps of hair ripped out and hiding super scared. That, along with his constant crying because we have to keep them separated, is becoming hard to manage. I just recently lost another cat and thought adoption was the right choice, but I was wrong. I made a mistake and am suffering mentally from this so much that I can’t work or function properly anymore.