He raped me and why do they blame me?

My brother in law raped and molested me over ten times. I was fourteen and after the first time I was scared and felt powerless and everytime he would do it I would just lay there. I obeyed and did everything he told me even lie to my sister. For many years I pretended as if everything was okay. But now I am older and a mother i can no longer carry the burden that he raped me. When I told my sisters what had happened they blamed me and said I commited and allowed him to have sex with me. My sister supports her husband that I seduced him and that I opened my legs to him. He recently tried to tell me the reason why he did it was because he wanted me to be his second wife. He is Muslim and I feel so disquisted and nasty and useless. I am mad at myself for even saying anything. My sisters told me at age 14 I was not a child so I should have know better. I am starting to think of suicide what can I do? I can't stop the memories of the rapes from flashing in my mind and my sisters condeming and making jokes of the situation. I feel so cheap and worthless