urinating during sex

[papperapple]

I've googled this to no end. I don't have health insurance at the moment, so I can't go to a doctor. Everything I've read claims that the urge to pee during sex is just g-spot stimulation- it's a female orgasm, just let it go, etc. But mine is not the clear, odorless liquid that's described. It's definitely 100% urine. It's yellow and it smells like pee.

I'm 25 and this only started happening about a year ago with my current partner. I've been sexually active since I was 17. It's not just sex that does it, either. I can easily reach about an inch into my vagina, and press on the upper are that comes right after the urethra, but this causes me to urinate. Sometimes a trickle, sometimes a lot! I've tested this in the shower with a vibrator to see what will happen if I just "let it go", and what happens is I pee. It doesn't just happen once and then my bladder is empty, either. I can continue pressing on or stimulating that spot and very small amounts will continue trickling every few minutes.
One thing I've noticed is that area in there seems to swell and get kind of hard afterwards. There is no burning, itching, discharge, or anything else going on. What could be wrong with me??

Thanks so much in advance if someone can clue me in on what happened to my vagina/bladder all of a sudden. X-posted to other forums to find an answer.