I'm sorry I know this is very difficult!
To be honest, the subtypes don't really matter. They're helpful for conveniently categorizing specific themes of intrusive thoughts, but if you worry about whether you have this subtype or that, they end up doing more harm than good. At the end of the day, it's all the same mechanism in the brain. It's the same obsessive-compulsive cycle.
The remedy is the same regardless of the subtype: allow the thoughts to be there without trying to fight them, solve them, or figure out what they mean, then allow yourself to feel the anxiety that comes with them without trying to push it away.
When you get thoughts like, "Did I cheat?" "Am I a horrible wife?" "Is this normal?" etc, the most therapeutic response you can give is, "Maybe, maybe not." I know that probably fills you with anxiety, but that's okay. This whole cycle is kept alive when we search for 100% certainty, because 100% certainty is NOT possible.
One of the most common worries people with OCD have is, "but if I had the thought at all, doesn't that mean something about me?" In reality, thoughts don't mean anything by themselves. Every human alive gets intrusive, unwanted, or just random thoughts. Even the most gentle person on the planet has had random thoughts of hurting other people, and the most loyal of partners have fleeting arousing thoughts of other people.
The main difference between people with OCD and people without it, is that most people without OCD might notice these thoughts for a little bit, then simply...move on without much care. Their brains are literally able to "switch gears" to another topic. People with OCD see every distressing thought as a threat that NEEDS to be dealt with, or else something bad will happen, or it means something bad about them. OCD is like having an extremely sensitive fire alarm that goes off if it detects the teeniest, tiniest spec of smoke in the air. Treating OCD means retraining the brain to let things go, NOT getting rid of the thoughts in the first place.
I understand the desire to be perfect, and to be completely sure that you are as faithful as possible to your partner, but at some point we all need to loosen our grip of certainty and focus on the here and now. As the other commenter said, here and now is what matters, even if you did (and especially if you only *thought*) of something you weren't proud of in the past.
Hope this helps.
