Is it abuse if I fight back? He didn't do anything yet this time. But, he tempted it.

Depends. I’d see it as self defense

It’s not abuse to defend yourself by any means. You shouldn’t have to just take blows. It’s crazy that you brought this up though because I’ve had the same thought before and have also wondered if was abusive for considering fighting back. I felt angry and hateful. I hope I never feel like that again. I think the only thing truly preventing me from fighting back is knowing how much bigger than me he was. I was always scared I’d only make things worse for myself.