What you are describing isn't OCD, so this probably isn't the best forum for you, but you are describing a pretty bad case of health anxiety. If getting a handjob upsets you this much it's time for therapy. I hope it helps you, as your problem is anxiety. Peace.
When you search the internet for penile cancer, you are imagining yourself to have a disease that you DID NOT get from a handjob. People in the STDs forum have already told you that it's not possible to get HPV, or any STD, from a handjob.
Walk away from the computer or your mobile phone. Go do something where you do not have access to Google for diseases that you cannot and do not have. If you are still irrationally concerned about this no-risk event, it may be time to seek mental health help from your doctor.