Married but gay

Hi, I'm 36 year old woman, have been married for 7years and have young children. My problem is I believe I'm Gay. I've questioned my sexuality since I was 15 or 16 but just brushed it aside. I have absolutely no sexual attraction to men whatsoever (even though i pretend to infront of family and friends) and fantasise about women all the time. I feel i've missed out on so much and am living a lie with my husband but I'm not brave enough to do anything about it plus i don't want to hurt my children. Does anybody know of organisations to help people like me. I would appreciate any advice.