Im at a loss and have mixed feelings?

Been with my boyfriend 2 months...he smokes weed and he smokes ciggarettes and hes done other drugs in the past most of which he says was "a one time thing" and i really dont like any of it and i constantly tell him i dont like it please stop and he responds by saying if u cared about me u woudnt mind but its also little things that he does that piss me off we get on each other nerves constantly and hes a big baby no backbone at all he says he is in love with me and everything and i guess i feel strongly for him to but now hes jumping to me spending christmas with him and its freaking me out and we have already had big fights and broken up twice hen back together and now i dont feel the same for him but everytime i go t end it i hesitate and then dont do it so now im like leading him on when im with him i feel weird and i feel like i can do better but without him ... then i just want him back idk if its because i dont like being alone or what but im confused ...advice please