Suggest Treatment For Intermittent Anxiety And OCD

Hello. I have been going through this anxiety for about 4 years now on and off and I m doing my best to get through it. I have been with my boyfriend for over 5 years and I have a fear of cheating like I already did it. It s mainly an obsession of kissing someone I know. It s like I have to constantly replay the scene over and over again so I can remember every little detail and it drives me nuts. If I hug someone or if a guy is too close to me then I start to feel like I made out with them. In the past I have had hundreds of situations with different guys and I proved them wrong that they were not true. I see a Therapist and he says I have OCD but it s hard to believe I have it because it is so real to me. I just don t understand why I m going through this because I m so in love with my boyfriend and I don t get why I feel this way. He is very supportive throughout this whole thing and believes in me and trusts me. I just wish I could believe in myself. Please advise, thank you!