How do you know you’re heading into an abusive relationship?

I have been seeing my partner for nearly two years on and off a lot of it not official.

Reason being he smokes weed excessively & I didn’t feel comfortable being around that all the time. Don’t get me wrong, I’m okay with it, just not when you become reliant on it to get you threw the day and have it every so often. Anyways a few months back he had promised me to stop doing it as often as he wants to get his act together to better himself. He’s currently unemployed with no license. But I’m so supportive of him. The other night he finished his game of footy. We had made plans all week for after his game to hangout as we hadn’t seen each other in a little while. When I got there all was good, but an hour into it he told me he was going to smoke weed with his mate. He asked me if I cared and I said the truth. “I care but If you want to that’s fine I just don’t want to be here for it so I’m going home” and he got so mad. He started punching walls & crying telling me how much he hates himself and his life saying he wants to end it. I told him I was leaving and he guilted me into staying but I felt bad bc of the state of mind he was in. Last night we were doing the deed and his bed was creeking bc it’s broken and he punches the head board above me & storms out bc it annoyed him. Idk what to doooo