You need to talk to a specialized therapist and unpack your anger issues. Right now your boyfriend is in an abusive and toxic relationship. y'all are both young and this could ruin his and your mental health. it seems like you're wondering why you lash out at him and strangers on reddit wont be able to tell you why. Anger issues stem from somewhere, talk to a therapist so you can figure out what happened to you and after you do that, then you will have to spend years unpacking those issues. then once you become a kinder person thats when y'all should consider dating. but as for now get therapy.