I you have trouble with your ovaries removing the uterus won't help - that's a bit like removing your hand to help shoulder pain.
Because your ovaries (cysts or not) produce hormones that are required to keep your body healthy most docs would want to leave them alone as long as possible.
Have you had an "endometrial ablation" for the endometriosis? It *might* help (no gurantees but less drastic than a hyst)
if you talk it through with a doctor and s/he decides that a hyst would be right for you you would be looking at removal of the ovaries as well. This would require you to take synthetic hormones for the rest of your life to help protect against things such as osteoporosis.
Having some sort of shot that causes menopause (never heard of such a thing so will have to go and investigate) would be a really bad idea. Menopause is when the ovaries stop producing hormones and given you are only in your mid twenties - that isn't a good idea.
Those hormones help control things like bone strength, skin elasticity, hair growth (you are very likley to notice skin and hair get thin and dry when hormones stop being produced)
do think very carefully, hon and do have sit down discussion with your doctor about treatments available to you.
Hysterectomy is a permanent last resort and not something to be considered lightly - it is also a major surgury. Usually requiring up to a week in hospital and a recovery period of 8-12 weeks to get back to a "normal" routine and up to 6 months or more for complete healing.