I'm not going to judge you because I'm not in a position to do so (nor really is anyone here). From your post, though, you seem to know the whole situation.
Here's what you may consider doing:
1) Stop the HIV research.
2) Stop having sex until you get tested, protected or unprotected. You realize it's unfair to put someone in a situation like this because you're in denial. Artificial sexual aids are available on the internet if you have an itch that you just have to scratch.
3) Get counseling or at least some form of social support. I'm repeating my standard list of clergy, friend, relative, or mental health professional, but you may wish to limit the scope so you don't face social problems. They will help you muster the courage to get tested, but this validation-through-sex issue will probably require the services of a mental health professional.
4) Not getting tested is actually what's not the option here, and you know it. You're aware of your exposures and you're aware of the symptoms. I'm sure you even know the testing period, so please do this. You can't go back and change the past but you need to know what your future is going to be like.
Good luck to you!