OCD and Intrusive thoughts on incest

Hi,

I dont really know how to start. I have been suffering from a mild form of anxiety for most of my life, but it was only in my 20s (I am 24 now) that it exploded into what I have realized maybe OCD. Of course, there was the typical fear of not having locked the door or having left the tap running but fortunately, I have been able to cope with those. What leaves me a complete emotional wreck are the intrusive thoughts, every time I feel like I am finally at peace my anxiety will pull up another bunch of thoughts that seem to be even harder to refute than the last. When I was in my teens I accidentally stumbled on some incest erotica. I wasn't looking for the genre but just came across it in another category. I read it and was oddly titillated but it wasn't because of the relationship between the two people, that never even entered my mind, I think I just blocked that part out and made them two strangers or something because i never even acknowledged that it was incest, to me it was just sex. For years this instance never bothered me until my latent anxiety bloomed into full-fledged Pure O OCD (I think that is what it is called). Every new intrusive thought is harder to deal with and this by far is the most difficult. I keep telling myself that I am not interested in incest. It makes me sick to think about it but my brain keep bringing up what i read, that didn't make me sick, so what does that say about me as a person? How can I accept something that is so awful and based on something I actually did, what if I really don't think it is wrong, what if I am a monster?

It all snow balls and soon I feel like I shouldn't be with other people at all, they deserve someone who is healthy and normal just like they are and i feel like isolating myself. I have an incredibly loving family which makes me feel even worse since I feel like I am letting them down. I am trying to deal with my OCD in a constructive way by channeling my energies, practicing mindfulness and trying to distance myself from my thoughts but every stumbling block I hit makes me fall that little bit harder and there are time I don't feel like i even deserve to get up because what I fear it true. What should I do?