I've been together with my boyfriend for half a year. Everything was perfect, even tho he loses his temper sometimes but you know, that's fine. I'm not calm either when something pisses me off. But today he started asking me about something that has happened more than 5 months ago (when we were together for one week). I didn't know him that well back then. Basically I did go out with friends and got high but didn't tell him about it. Actually I lied about it, i told him I'm sober that night even tho I clearly wasn't. I told him the truth about that night one month later. Idk why I didn't want him to know at first. I guess I just didn't want to fuck up in the beginning of relationship.

Well long story short we were talking about weed today and he suddenly remember that night and started asking me questions about it. I felt like he was trying to find a reason to be mad at me so I snapped at him telling him to stop, that it happened long time ago and I wouldn't do it now.

He was really very pissed about the fact that I lied to him - and also that there were boys with me that night (even tho I didn't even touch them, we just sat next to each other)

I got a little angry because I felt like he was trying to fight with me so I shouted at him to stop and that's when he caught me under my neck, so I slapped him (for the first time ever, but this has happened too many times before so I guess I want to show him I'm not gonna let him do whatever he wants) and he decided to slap me back. Three times. when I fell he pulled me up by my hair. Of course, his slap was worse, it was really painful. He is very strong, he also used to do kick box.

Now my whole cheek is swollen with purple bruise and something that looks like scratch idk.

Tell me what should I do? Can I consider this abusive? How can I make him stop? I dont want to break up with him, I really don't. Please can you try to recommend me something else besides leaving him?