Don’t know what to do...

So there’s this guy that I’ve liked for a while now and we’re really good friends. About a month ago he told me that he was falling in love with me and after that we kind of stopped talking, I’m not sure why it just freaked me out. Well, the other night I hung out with him and he asked me if I wanted to “make it official” I don’t know what I was thinking but I said yes. I’m so bad at saying no to people and I was staying the night so I didn’t want to make it awkward. I am NOT a relationship person I don’t know why I just can’t do it. So now I’m in this stupid situation. He keeps telling me that he loves me and I just don’t say anything back because in all honesty, I don’t love him. I think there was a point in time where I really did but it just took too long and I got tired of waiting, I’ve moved on to other people. But now I guess he’s my boyfriend and I don’t know how to tell him I don’t want a relationship with him. Not to mention he’s had drug problems in the past and the night we hung out he was talking about how he was doing cocaine on nye and all these other drugs. I just can’t do it. I need help.