Tell me about endometriosis

I have VERY painful periods. My cramps are on another level of painful it seems like. I vomit, I’ve passed out, my legs go numb and I can’t walk, I get cold sweats and chills. Recently I’ve started to get really bad headaches during my period and it blurs my vision. I use to think it was normal because my sister is like this too but when I explain it to friends they’re like um no that’s not normal. Now I’ve told my doctor about my symptoms but they’ve never even mentioned endometriosis.