Who do you talk to when you feel there is no one who would understand?

You have something that really bothers you and is so private that you cannot talk to anyone that you can think of. It's so private that you wouldn't even tell if you called off the wedding. I feel like I am the only one with this issue. I can't tell my Mom,sisters, best friend. My therapist moved and I have tried several others and no one seems to click yet. I easily could have talked about this with my old therapist. I have tried calling her and since she is out of state she can't talk with me, she has apologized for this several times. Every time I try to talk to my fiancee about it he doesn't understand and thinks I should understand his point of view. I have even told him this could be a deal breaker. The only thing I can say about this is it has to do with sex. This matter had to do with the breakup of his last marriage. It's already affecting our relationship. I'm older and my sexual preferences are pretty much clear but this steps out of my boundaries. I have tried it and unfortunately there were some parts I did enjoy, I just don't feel there is any reason to go there again He seems obsessed with it and wants to continue and it is causing problems for me and how I feel about myself. I have een told him this. So does anyone have any ideas to help me sort out my feelings? I've tried everything I can think of.