Endometriosis?

Idk what's going on but I don't look forward on the time of the month. My cramps are really bad to the point to where I can't get out of bed and i just hurt overall. I don't eat at all or when I eat or drink I vomit. I've been to the emergency room numerous of times during my period but they all say the same thing. They say I'm backed up with poop and they give me laxatives and go. I need help. The pain medication and the PMS yoga don't work. I even tried music. Gosh. I hate it because I miss school on certain times of the month or my plans are ruined. I really do need help but Idk where to start.