I can understand being disgusted by the oral sex with your husband - the end result specifically. You are right that many people find this disgusting and won't engage in it. Although, there are people who love it too, and people who just tolerate it, with a take it or leave it attitude. However, I don't think this is what triggered your repulsion/phobia and other obsessions. I think your issue goes way back to your childhood. This is where most of our issues begin, sometimes overlapping later traumas as well.