Possible Endo?

I'm twenty, got my first period at ten, and since then my periods have become more and more painful each time. It was so bad that I could not move from a certain position without severe cramping, dizziness, intense lower back pain and nausea. I was put on BC at sixteen, not sexually active then, and that lessened the pain for a couple years, but didn't get rid of it completely. After becoming sexually active at eighteen, the pain was so severe I couldn't stop crying. Pain during, before and after sex, pain trying to pee and poo, pain sitting and pain standing, just constant pain a couple days before, during and after my period. I continued complaining to my doctors about the pain, but they usually told me that it was no big deal and other women have it worse. This made me feel so deflated and I honestly lost a list of faith in doctors after years of being told that it was normal to feel this way. 
My mother had a full hysterectomy at 30, due to Endo and strongly recommended that I continue going to the doctor. I finally did because I want to have children, hopefully soon. 
I have had ultrasounds and blood tests, and my doctor suggested PCOS, but didn't make an official note on my record. I even did a glucose test to try and rule out PCOS, ( totally gross and so sickening ). I went to the ER at least once a month with heavy bleeding, at least a pad or two an hour, and the above mentioned symptoms. I was in agony and the hospital just drugged me up, giving me more to take home, and sent me on my way instead of trying to help me. I just couldn't do it anymore, I'm in constant pain and being in a dazed state is not living. It's not solving the problem. 
FINALLY, now that I'm twenty I have a consultation appointment with a gyno, to move towards a laparoscopy. I'm both excited to do it, and dreading it. I'm excited because I might finally have the answers I've been looking for, and possibly the cure to this constant pain. But I'm dreading it because it has been at least six years of this pain, and I've constantly been cut down by doctors. I'm scared that it might be too late to avoid any damage to my reproductive organs. It would destroy me to be told that I can't have children. 
Anyway, I want to know what any of you think, do you think it's Endo or PCOS? What are my chances of still being fertile after six years of issues ?
How did you prepare for your lap ? 
How long did it take to recover? 
Sorry for the long post, I'm just really in need of some help, and someone who understands. 
Thanks in advance x