Why are some people so sticky ?

So the thing is I am studying in a decent private collegee . But i didnt get in here through management quota. Now I made a Bengali friend here and I am Bengali too. It was he who first advanced his friendship. Okay and alright. But the thing is our friendship is really getting in my way and getting even more toxic day by day. He frequently ask me for money and then does not repay b Ack and often he also pretends to forget about it. Next he often forces me to come with him for a cigarette or even t ea even when I am studying in my room and does not respect my personal boundaries. And I don't know why but he often makes fun of me saying that I got in here through a management quota and that he has doubt about my academics. Things like that really hurt . I have often told him that I do not want to continue his friendship but he never seems to take me seriously. He also is much more stronger than me and even more persuasi ve .He is even forcing me to tell my parents that i want to be his roommate from next sem or else he will tell my parents that i smoke . I am really at a loss of words as to what to do. Please help me out.