I really need help on this :'( its long but i really need help im stuck, help?

My bf and i have been together for almost three years now and i am getting tired of how he is. I used to be with my family a lot and be happy gng out and stuff. But he doesnt like that, he doesnt let me look up or see any guys, he gets mad when he doesnt get to be with me even if its for a couple of hours. I want to hang out with my family because i love them and i miss them, he tells me what to wear all the time, i cant wear any kind of vneck cause it "shows everything" so i have to wear tshirts and i cant wear shorts either just pants, i have to tell him what im doing or going or anything even if im in my house, i cant go out to the front because guys might p by, i have to tell him EVERYTHING, i am getting tired of it, i have left him twice and he said he will change and he hasnt, just that he hasnt gotten mad as much as he used to which was every single day. I cant tell my family because they will get mad, so what do i do? He doesnt hit me though but there has been times that i have hurt myself, even cut myself, and last week he got mad at me for some stupid reason that made no sense and he went outside and i punched the window and broke it and started bleeding, and he kept hitting himself in the temple, and two days ago he was telling me he was gng to kill himself and it was gng to be my fault cause i said something and he took it like i was calling him a f.a.g.g.o.t or gay, whatever. And he hates my brother and he didnt do anything to him, my brother is gay thats all, and he hates that and it discusts him and i love my brother, and i want to go to his house and have fun but he wont let me because he doesnt like my brother, i go but i sneak it, saying im asleep and i have so much fun, and dont worry he will get mad, and i even forget about him and im happy, but its so hard cause i love him more than anything in the whole world :'(. Im afraid ill be bored and wont find anyone else for me, because we already planned out out lives together