The whole story's kind of long, so I'll give a tl;dr at the end. I'll start by saying that I'm 20, male, and have never had sex.
The first time this happened was around Nov 2017. For a few weeks prior there was a slight burn after climax that went away within a minute or two, but I didn't really pay attention to it. I finished like normal and was completely fine, but after about 10 minutes this pain started to linger around the tip of my penis. It got worse and worse until I ran to the bathroom to pee, and all of a sudden there was this white hot burning pain (like an 8-9 out of 10) right around the opening. I took a few ibuprofen and walked it off, but the pain wasn't even manageable until about three hours later. This has been recurring ever since, but I've tried getting help multiple times.
The first doctor I saw said that I had an 'erosion' problem (I am cut and often masturbated without lube) and gave me an ointment to heal the skin. I used it for a week and while that problem did get fixed, the pain didn't get any better. My urine tests came up clean, but he still prescribed me azithromycin to rule out infection. Again no change. After this he referred me to a urologist.
This first urologist, who I saw Dec 2017-Apr 2018, thought it was a bladder issue and put me on the IC diet, but after a month of that there was no change in pain. She prescribed me Uribel, which I've been taking ever since and has helped a lot with the pain. I should mention that at this point there's a constant lingering pain that's mostly easy to ignore, but gets much worse when I pee if I'm not on the Uribel. After a dose of doxycycline and a few more months of nothing she says the next step is tests and suggests a cystoscopy. I had one done in April and the doctor said everything looked fine and that it should clear up on it's own. The unbearable pain hit me just as I was walking out and lasted for a few hours.
The problem never went away so I saw another urologist in July 2018, who looked at everything and gave me a prostate exam. He said my prostate didn't feel enlarged but put me on Saw Palmetto for prostatitis, which I've also been taking ever since. Around this time I also started using a 5% lidocaine ointment to deal with the pain on climax. I wanted to be careful, but waiting too long without ejaculating made the pain even worse, so I eased back to masturbating every month or so.
There was a period where the burning didn't totally leave, but was subdued enough to masturbate without having to worry about it getting unbearable. I think I was climaxing almost every day without issue for at least a month or two. But it hit me again around Nov 2018, just as bad as the first time it happened. I saw another general doctor and had a few urine STI tests done as a last resort, which all came up negative.
Less than a month ago I climaxed on ibuprofen with the lidocaine ointment, which has honestly turned into a monthly routine, and despite all of that the pain came back almost full force, maybe a 5-6/10. It's the first time that's happened and at this point I have no idea what to do. I know I should see another professional, but I don't know if I can deal with another round of negative tests and a hospital bill. Does anyone have any experience with this kind of pain or any more insight?? I've seen posts about things like nerve problems, but haven't looked any further into anything.
tl;dr I haven't been able to climax without an unbearable burning pain for over a year and a half now, to the point where I have to completely avoid it. I've seen two doctors and two urologists, had countless urine tests, and have so far been cleared for UTIs, STIs, and bladder disorders. Where do I go from here??