Boyfriend addicted to 'spice' and is acting horrible, help me ASAP!!?

He's been to rehab but when we first met he was sweet and caring towards me since he didn't smoke much, recently I noticed that he becomes a idiot and major DB when he gets high, I tell him not to smoke anymore of that stuff and he's had enough and he smokes more anyway laughing in my face...last night I spent the night with him and he was sweet when I got there but he smoked spice and he became really rude calling me stupid, I asked him to get the dog off of the bed nicely so I could lay down and he said "nah bit** you can get out then" so I did in my underwear and shirt and sat in his brothers room crying...I went back to the door of the bedroom a hour later and he locked me out...I knocked for a hour and 1/2, I called and called...I sat on the floor up next to the door knocked until he finally opened it telling me to stop being a stupid bit**...I layed on the floor, when he told me to get on the bed I did and he mocked me...saying "boo hoo, cry about it!"....I'm tired of it :,( help