abdominal pain/endometriosis?

Amanda
So I've been dealing with horrific pain near to my right ovary for about a week. I've had cysts in the past, and this has hurt 2 times worse than when I had a cyst rupture a few years ago. 
I went to the ER today to get tests and ultrasounds done and they found...nothing! No cysts, tumors, no torsion, no appendicitis or kidney stones, no ectopic pregnancies (or any pregnancy at all), no UTI...nothing. While I'm grateful that it's nothing serious, I'm very frustrated because the pain is persistent. 
My breasts have grown tender and my period started early as well. I also have a HIGHLY diminished appetite and feel uncomfortably full even four hours after a meal. I just turned 21. I was googling stuff and the only thing I can think of as a last resort is endometriosis, but the only symptom I have is the pain in my abdomen...I'm nervous to ask for a laparoscopy because the idea of performing a minimally invasive surgery for what could not be anything seems daunting but the pain has reached a point where it's difficult for me to go to work or to class, or even really function. Any ideas, healthy savvy/health workers/ppl with diagnosed endo??? I'm desperate