Check out The Endometriosis Diet. I got my own endometriosis under control by doing 3 things:
- Very little / no refined sugars, including bread from ovulation until day 1 of my period.
- Switch to washable pads / moon-cup. Disposable absolutely give you pains, it takes 3 months but the difference is incredible.
- Take 1 ipuprofen 3 times a day from 2 days before your period is due (it builds up unlike paracetamol and prevents inflammation) and then normal dose from day 1 of your period if needed. Ibuprofen also reduces the amount of blood you'll lose.

Also take vitamins and evening primrose oil for your mood and when you get stressed talk to yourself kindly, as though you were another person; "You will be OK tomorrow, it's just hormones, you can do this."

Finally, get a TENs machine, I've hugely improved my pains but I still have them a bit. But if I do all the above and then put on my TENs and take 45 minutes wearing it, lying on my left side and watching TV or reading as soon as the cramps hit, I can usually breeze through the rest of my period like a woman on a tampon advert! (My periods used to be much worse than childbirth and bloodloss was crazy.)