So sorry this has happened to you and the rug has been pulled out from under your feet. You must be numb and nauseous.
A couple of things really stand out here though and nearly everyone has picked up on them:
He was at a strip club, which he had been to before but not told you about - so yes he is very capable of lying, and obviously has been lying for some time. This isn't out of the blue...
He was out with one friend? That's not exactly group frenzy on a boys stag in Prague (not that it's forgiveable but the egging on etc is common) - so they both sat and discussed it and formed a plan.
They walked around for ages looking for a brothel - so there was intention.
He went in alone - so no excuse that he went in to talk a mate out, just sit there and wait for the skanky mate etc - he made up his own mind to go and perform a sexual act for money. (to further solidify this why not check the bank balance and withdrawals for that evening. Chances are he was sober enough to calculate the cost and stop for a cash withdrawal).
On these "boys" weekends home, he books a hotel? He can't sleep on a mates sofa or floor, or spare room because? He brings back women, his mates bring back women, he wants to do something that he doesn't want his mates wives to hear about. So these are planned activities too?
He told you the "truth". Either because he's got an itchy penis which is turning into genital herpes, and has to fess up, or is he worried that one of his mates wives found out and is going to fess? It all sounds a little odd, but if he feeds you a slightly shameful story that's forgiveable with time then he has a chance of making it all die down after a while, and hope you never find out the full truth.
You can get an std from bjs - if the sex worker in question has oral herpes. Which sounds to me like a street worker type, if she was willing to bj without a condom for a little more risk money. If that was the case, then please remember that some of these women are even more vunerable, does that make you feel proud of your rock?
So..still convinced?
The ball is now entirely in your court.
Only you know if you can ever trust this man again.
You will need counselling as a couple.
You both sound as if you need to stop drinking.
You as an individual will need screening for STD's. I am so sorry on your behalf that he has caused you this suffering, pain, embarrassment and possible disease.
If you are going to make it through i can't see how he can upkeep these childish friendships and your relationship. Something will have to give.
You will have to look at him everyday and wonder what he is thinking.
You will have to make him appear a proper "man" again in your eyes, so that your friends and family respect him, and your prospective children do too.
If you still plan future family (if you ever get that far) you will have to have sex with him and give yourself unconditionally, if you can do that.
If you have children, and you go off sex for a bit, as we all may have experienced, will he look to the brothel, or put pressure on you to do things to stop him looking elsewhere, putting the power firmly on his shoulders?
When he closes the door and leaves you will have to trust that he is doing what he says he is all of the time, as the only other options, as many of us on here know, is a slow churning insanity.
Does he still look like your rock now?
Does the other guy's wife know?
Either way for a little time he needs to sleep in the spare room to give you time to make your own decisions. I hope you find some peace, this is just awful.