I have a similarly overactive imagination and I feel trapped in my mind as well. I constantly seek reassurance that I'm a good person. My ocd fear is hell and I get terrified I am going there. Can't stop asking what if I go? What if I'm lost there forever all alone and no one can help me? I am trying to get through this but it's been a year now of the same.
As a fellow OCD sufferer, I cannot give you reassurance. Even if I did, you will still find a way to be anxious about this situation. The best thing is to stay off Google, let your mind and heart calm down over time, and accept the very unlikely risk that you could have contracted hiv by kissing. Your worried OCD mind is making up other what if scenarios based on fear. I go through this all the time, constantly worried what if this happened and what if that happened. It is so frustrating, but I always find given time the worry goes away if I do nothing about it.