Wow...Mustang...what an ordeal and what a life you've had to endure. First, I'm so sorry that you're going through this. I was molested from the time I was 12 until I was 18...didn't talk about it or go to therapy until I was in my late 30's...I went to an incest group and found out so much about myself and got the help I needed.
In my therapy, there's a place that sounds like where you're at now...the little girl who was betrayed by the ones who were supposed to love you still looking for approval and acceptance and inclusion. But, honey, you have to realize that your family have their own huge set of problems and a lot of that is to place blame on the one they've done this to all your life...you. YOU are the one who has to make the change for yourself and the first thing I would do...if I were you...is to find a really good incest counselor/group. Not just a regular counselor...but one that specializes in incest. That's important. I can hear your desperation and you have so much poison within you that it sounds like it's finally festered to the surface and is bursting to get out...I can hear it in your words. You need major outside support right now in how to deal with your feelings and not anyone else's. Your counselor should be able to help you work through things as you tell him/her about them....but, until you allow this little girl inside you to get everything out to a counselor, she's never going to stop believing the things these people are telling you and she's never going to stop trying to find approval from people who probably never will be able to give it.
What you may not realize fully yet is that the answers are all within you. The approval of yourself has to come from within you. And the acceptance of yourself...and all that entails...has to come from within yourself. It's all there...it's just all hidden by your life and how you were/continue to be treated.
It's easy to say you've got to stop letting people treat you this way, but when that's all you know and it sounds to me you've got some doozies who are experts at guilt and manipulation...it's tough. You aren't going to do this alone...I hope you'll be able to get some counseling and start working on what's important...and that is you...wonderful, sweet Mustang.
But, for now please do me a favor. Put your arms around yourself and the little girl I know is inside you and squeeze really, really hard. Tell her you love her...tell her you're worthy...tell her you will find a way for her to get out and be free of all this. Then tomorrow find someone you can talk to that's a professional. I speak from experience. It was the best thing I ever did and just dealing with the incest alone will make such a difference in you. If you can work on that, you will be amazed at how much inner strength you will discover and will surface. You're tougher than you think sweetie...I know...the little girl in me was found, was validated by no one else but myself and you know what?...that was enough. That's all that's ever enough when it comes down to it. We are all we have...so, I hope you'll think about this and begin to change your life by getting help for that little girl first...we love you here and you are important to us.