I am 27. How can I convince my doctor that a partial hysterectomy is appropriate for me?

I have suffered from painful dysmenorrhoa and endometriosis since the age of 13, but barely got diagnosed last year when i had a laparoscopy where they removed an ovarian cyst. I have been on the pill for almost 10 years and am afraid of the long term affects they may have on my body. My periods have not improved; i get sick all over again once i stop taking the pills and at one time developed cysts in my due to the type of pills taken. My husband and I have decided we do not want children; i have a great career and can finally afford college and get my degree in photography. Children are nice, but i have no desire to give birth; to be honest, to adopt an orphan or foster child thrills me more than anything and seems to be the right thing to do. But when i discuss having a partial hysterectomy, even with my condition, i am easily dismissed. What do you recommend I do to get what I have considered for years as a health option for myself?