I was diagnosed with endometriosis when I was 18. Generally, it's a pretty crappy disease. It's different for every woman, no one's exactly sure of the cause, or the cure. There's a bunch of theories floating around, but like I said, no one really knows.
It all started when I was about 14. I was having the most unbelivably painful periods. I mean, I'd be in bed for days at a time. My flow was terribly heavy. I was going to this doctor and that one, and no one figured it out. Four years later I had my laporoscopy. While they were inside they removed a 3 inch cyst, and lasered some of the endo.
For me, mostly it doesn't bother me. After my surgery I was put on Zoladex for six months. That was a big mistake for me. It totally threw me and my hormones out of wack. After that disaster I was put on regular birth control, still not much help. The pain was, and sometimes still is prety severe. Now I'm on bc all the time. No break between cycles, thus no period. I"m doing ok, but I still have my days when I can't get out of bed, but they are few and far between.
There's all kinds of websites out there to help. At the bottom there are links to the ones I've found the most helpful.