Re: 19 year old, period for >15 months
This must be a miserable situation to be in, I am so sorry!
In this case, (and most medical situations) you have to take the bull by the horns and continue to see your doctor until you have some satisfaction and a reliable diagnosis that includes a treatment plan.
If the doctor you are now seeing does not offer you anything, you will need to ask him/her for a referral to a specialist. It there are tests you feel you need, then by all means ask the doctor to perform them or have someone else do them. Just don't give up until you get your answers. It can take time to figure out some situations, but stay with it.
You can always feel free to get other opinions from other doctors too. I had a situation last year that took me all year to work out, with appointments at umpteen doctors. Eventually one of them got to the bottom of it, but not after serious pain for about 8 months straight.
I am hoping that another poster will come along and know exactly what the name of your disorder is, and has experience in overcoming it. I wish I knew the details, but I only have experience with having a hard to diagnose illness. I wish you the best!