Very Scared - Tender Ovaries Extreme Fatigue

I am posting here because I feel as though I have no where else to turn. I am 22 years old, and have always been in good health, up until about two months ago. I first noticed a pain in my left side above my hip which crept around to my back and down my pelvic region. The pain was not severe, but very noticable. After which I got my period which lasted for fifteen days (normally seven days) at the end of my period I had "new" bleeding compared to the normal brown end I normally have.
After my period, the pain started again in the area next to my right hip. I went to my general practitioner, who performed a pelvic examination and didn't find anything unusual at that point. I was also having trouble taking a full breath - my blood pressure was normal, my blood oxygen level was normal, and she said it was my anxiety. After a week of no improvment, I went back to her, and she did another pelvic exam, found nothing wrong, and put me on amoxicillian on the off chance I might of had an infection. Three days later, I got a stabbing pain in my lower back, and went to the er. They checked my kidneys, which were normal, and checked my cell count, also normal, and sent me home. I went to a chiropractor, who ran x-rays, which showed that I have a curved spine, but showed no other abnormalties with my organs except for an excessive amount of gas in my intestines. I then went to a gynecologist who again did a pelvic exam and found that my ovaries were tender to the touch. When he touched them, a shooting pain shot up my back. He said I most likely had endometriosis, though he couldn't tell for sure. He based that on the fact that sex has always been painful for me, i've always had heavy periods (though never prolonged, and never had any pelvic pain). He also did an ultra sound, but didn't say if he found anything abnormal. He put me on birth control pills. My pain is continuing up into my ribs, and severe pain underneath my shoulder blades, particularly my left shoulder blade. It is to the point where I have to take massive amounts of ibuprofin to get through the day.
The pelvic pain is now on my right side as well, I am extremely fatigued, and my period this month only lasted three days, which has never happened before. I have no health insurance and have paid over a thousand dollars so far for no answers. I am very scared and just want to know what is wrong with me so I can start to correct it!
I am fearful of ovarian cancer because of my symptoms, also my grandmother passed away from ovarian cancer (though she didn't develop it until her late seventies). Can anyone with any knowledge of ovarian cancer inform me of the symtoms - everything I find online is very vague, listing only "abdominal discomfort" and "irritated digestion" - this has gone on for two months, and the doctors I have gone to see tell me that ovarian cancer is nearly impossible to detect, yet I keep reading that if it is not diagnosed early, the chaces for survival are minimal. I am aware that ovarian cancer in someone my age is very rare, but with my symptoms I want to make sure it is not something more serious, and begin any treatment I would need immediately.
Any insight would be sincerely appreciated. Thank you.