Dealing with a hitting toddler

My kid is three and has a sister who just turned one, he’s been hitting a lot lately, I’m thinking it’s because I’ve been giving more time to his sister because she breastfeeds and gets scared of his screaming (he is seeing therapies for any behavioural issues as autism and adhd and other things) and yea I’ve tried giving him time when she’s asleep or busy doing something else, I include him in things with her but he’s not having it, and I’m going crazy. (Single mom fleeing domestic violence) he punches me in the face and pulls my hair out, he dumps his entire toy box over his sister and pushes her to the ground, he slaps and Amos always running head first into my back or stomach.. I’m tired of it.. I love him so much but he is pissing me off with his hitting.. no matter how much I try to influence good behaviour and habits his sister is the only one who is catching on with the good behaviour and when she saw her brother hit me she hit me.. and I just can’t.. I’m breaking down because I feel like I’m doing something wrong.. I can never have visitors or go anywhere because he hits others and screams and runs away.. please don’t suggest daycare or anything I’ve tried that and couldn’t afford it with subsidy and had no ride there and back every week was a struggle and they got kicked out for missing too many days or late drop offs.. obviously their dad is not in the picture and I have barely any family out here just my mom but she drinks alot and works full time in a casino.. please tell me what else I can do to help and be more patient with him..