Did drugs make him do it

If you read my recent post about wat happen between me and my ex you'll see he beat me I'm 7 months pregnant with his baby I've been with him for almost 5 years I've never seen this side of him he has major depression but the violence just started randomly he started to change physically and emotionally I've never delt with bad depression before so idk how it effects different people I known he did cocain 2 times I think his friend got him on it he swears he was not on drugs and he was homeless for half my pregnancy but I just don't see how he could just lose so much weight like his back bones were showing I can't heal my wounds  without a explanation I know he'll just blame it on his depression and stress but I think there's a whole lot more to his jealousy and crazy accusations he's in jail I haven't talked to him but I want to write him cuz I want to fucking know why did he hurt me this bad I loved him and still do but my child will not be around this I can't do it anymore