I need advice...

So I’m 17, I’m an American girl born to Dominican parents. I feel like In my house I have no say in anything I do, I’m told who to hang out with, when and where I can/can’t go, what to believe in etc., simply because that’s the way it’s always been. I’ve always had an attraction to girls but just recently I came to the realization that I’m bisexual. I had many boyfriends, and 2 very short lived girlfriends. However because of the way I was raised I’m not allowed to date and I do all this in secret. I’m scared to tell my mom because I know she won’t be supporting, and I don’t know how to exactly, any advice?