Help me plz! Relationship help!

Im not happy with my fiance. and i think that I am no longer attracted to him as his personality turns me off day by day as I start to see the real him unveil.he is annoying and always on my case. He makes everything his business and thinks he has the right to know everything. I dont like the way he uses drugs behind my back. I dont like that shit at all!All I want is space! I dont think I want a relationship. I feel completely turned off. I want my space and my personal things to be private. I want to be able to hang out with whoever I want to hang out with and not be judged by him!I have guy friends and have known most of them before he came into my life and he doesnt like the fact that I hang out or talk to them. Im instantly considered the bad guy in the relationship?And we argue endlessly! Sometimes i feel guilty about the whole situation and believe that I am the bad person and not being fair on him hence why im still in this relationship. Im also scared that if I do decide to get out of the relationship life will get more shit!Im not sure what to do! Its so fustrating and stressful.