I have OCD HIV too. I can tell you that meds really help break the mental cycle
You have to as much as its painful, to not give in to the compulsions which in your case is looking up medical information. Also realize when the thoughts come that as real as they may feel, that they are simply just thoughts. Its tough, but the less you feed into your OCD, the less it will bother you long term. So when the anxiety and thoughts come, label it as such that its just your OCD.