I'm just terrified that I'm going insane.
First of all, you are not alone! All your symptoms sounds pretty typical to me.
I am sure you would want nothing more than for someone to tell you that you are not going insane. Or, you want definitive proof one way or the other. Believe me, I have been there.
The reality is that definitive proof is simply not possible. And the only way you will break out of the vicious cycle that is OCD is to allow yourself to be uncertain. Instead of trying to counteract the thoughts of impending insanity, a healthier response would be to think 'maybe you will go insane, maybe you won't'. This will obviously cause anxiety. Letting the anxiety that comes with this uncertainty to just sit there, without you trying to solve it is the only path to relief. Eventually, and it does take a while, you will be able to tolerate more and more until uncertainty doesn't bother you nearly as much as it does now. Anxiety isn't fun, and what I am suggesting is easier said than done. The reality is that anxiety can't really do anything to hurt you.
Stop chasing the pot of gold at the end of the rainbow. The perfect answer doesn't exist.