What diagnosis can be made from these symptoms?

I'm 17 years old, not sexually active, and perfectly healthy.
I experience frequent urination, urge to always go, and a little anxiety about it in school.
I believe I also have a weak pelvic floor- my muscles down there tense up very bad.
I cannot use tampons, I've been trying for the past 2 years and it won't go in. I've tried everything & every angle as well.
I've been to a urologist, which she couldn't progress with the pelvic exam because I was so tensed up.
and I've been to a GYN, which in a few weeks I am going back to be sedated for an exam because they think I have a tough hymen.
Doctors have told me my bladder is perfectly fine but somehow I don't seem convinced because of the urination I experience.

Is there any way that the bladder/urinating issue can be a GYN problem?
Is there any way that these two issues are/are not related?
Why am I experiencing frequent urination at a young age?