Well, you have done a good job of getting checked out and ruling things out. Does not sound like an std (you've checked), hpv or any issues like that. How's your lubrication? I guess after months of this stuff, it would be possible that it would be hard to be totally turned on. Do you use an artificial lube that you may be reacting to? Or don't use any that causes you to then have the issue? Do you use condoms?