Abuse after Stimulates

My current boyfriend of 3 and half years never once put his hands on me until a year ago when he got put on adderall/vyvanse (stimulates). It was like the more he was on it the more angry he'd get and started putting his hands on me, jumping on me like attacking me to shut up during arguments using his arm to choke me, but then the other night he hit me really hard across my face. Have a huge black eye, definitely broke a blood vessel in my eye it's slowly getting more red and a huge lump above my eye. He immediately started freaking out about what he did I told him to get away from me and he did apologies like crazy, crying. I told him that he never put his hands on me before taking stimulates now look at him, he said he'll get off them that's not him he doesn't hit women. Every time he looks at me he has to look away because he starts crying. I've never had a man hit me. Now I'm confused because before he got prescribed those he wasn't like that and the very next day took less of what he normally takes wanting off it so he doesn't lose me. Now idk to stay or end the relationship. Could it be just because of the stimulates or he's just now letting that side show. Anyone been through this before or have any advice????