He won't let me go out

My boyfriend won't let me go out anywhere with my friends... he doesn't trust me one iota... although I do deserve it I guess... i lied and told him I wasn't talking to my best friend and he found messages between us. One of them saying "I love you" in a sisterly manner... yes, he made me choose between him and my best friend but she was cutting herself... how could I just stop talking to her?
He called it cheating.. because I was bisexual and I lied... he had no compassion for me when she lulled herself. Wouldn't even allow me to grieve...
Now because of that he won't let me go anywhere. And if somehow he does, he gets upset and yells st me... I didn't get to have a birthday party because it'd be a sleepover and my mom says no to mixing girls and guys..
I'm 17... I know I'm young. I just don't know what to do at this point... I went out ealier today and now he's yelling at me for going