ok, first off it could be any number of things. There are several std's that cause you to have bumps or sores. Herpes, Genital warts, etc.. But I would still go see a doctor. Just tell your parents that you think you have a bladder infection and it's really, really uncomfortable and you want to see a doctor. I'm sure they will understand and take you, then when you go in tell the doctor what's going on and ask them to do the tests I know your 16 but sometimes they don't even tell your parents what the problem is they just tell you how to take care of it and give you medication for it.
I do recommend though until you get this figured out, you don't have any sexual activity. Good luck with this!
If you can't handle the thorns, don't crave the rose!!