The best way I can describe what the pain feels like right now is when you need to piss like really crazy bad. (I don’t actually have to piss though.)

That sounds like residual sensation from a Foley catheter - basically a straw that runs up your urethra and into your bladder. Once in place, the end of it’s inflated inside your bladder so it doesn’t pull back out, but that balloon puts pressure on the base of your bladder, and that’s how your brain normally knows it’s full of pee.

So, if the Foley was in place for a long surgery, that part of your bladder might have been super irritated - very common when people wake from surgery for them to feel like they urgently have to pee but the Foley was removed just before wake-up or still in place and actively draining their bladder (so we know the bladder is nearly empty either way).

I’ve never been in that type of surgery, so idk if they would have even used a Foley, but if yes, that’s likely the culprit. If by ‘balls destroyed’ you mean complete genital conversion to include the penis, then Foley placement would make a lot of sense since that would act as a marker for the urethra’s location as incisions around that area obscure anatomic landmarks with blood. The irritation and urge sensation would also make sense, since the Foley would have been handled a lot, making your bladder tissue REALLY angry at that balloon.

If they left the penis alone and only operated on the balls, then /shrug.

Good luck with your recovery, and follow your post op instructions to the letter! That’s a high infection chance area, so don’t take any risks!