My fiance intimidates & makes me feel nervous, I feel i cant breathe around him! Advice, Mature Answers?

I am 25 and have been with the man i love for 3yrs, , my fiance is 35 and a champion bare-knuckle fighter. I am starting to feel like i cant breathe with him as he can be very intense, When he wins im the first one he will go to, kisses me and picks me up over his shoulder, Although i don't go to every fight as i feel uneasy seeing the blood etc. Other times if we are at a party he will keep looking at me or if a guy casually talks to me and im being polite telling them im engaged my fiance puts his arms around me or he will walk up to me & gets aggressive at the guy but when i tell him its ok and to relax he holds me close to him and the guy basically runs away. I have a full time job and when i get off the subway i just want a shower and chill out but as soon as i get home he is all over me coming up from behind me holding me telling me how much he missed me then he usually starts to feel me up which leads to sex, the other night after the guy was flirting with me when my fiance and i made love he started to slightly choke me, I got scared & asked him to stop he kept apologizing to me telling me how much he loves me, that i am his life and is sick of people trying to take me away from him, Other rime he seems to stare intently at me whilst making love which makes me feel a bit self conscious. Its almost like i cant move but he is there and his hands are on me in some way, He also has my name tattooed over his heart. I love him to death but he makes me feel intimidated lately. My bff and he don't get along at all, She never liked him, She says that he is no good, that he is unpredictable and that he's got no conscious, He tells me i let her influence me way too much. Despite all this i cant deny that i love him but i feel i he wants me in his radar all the time. This may seem stupid but it bugs me, Any Advice?