I'm not familiar with Depo, but I am with something called 'lupron'. Originally for testicular cancer, lupron is a self-injected medication that completely eradicates the menstrual cycle for as long as you take it-as long as 3 months. I don't know why you 'bleed like a stuck pig' and suffer so greatly, but if endometriosis is present, lupron, in stopping your cycle, stops that as well. Side effects of lupron, that at least I had, was just bitchiness, so no one really noticed a change.
lupron
A friend of mine decided, also at 30, that she would never have kids and had to really badger her doctor into referring her for a tubal. That 'what if you change your mind' crap is just that-don't fall into the trap. If someone is that insistent on discussion, say "I'll adopt. Pass the pepper."
You DO have choices, you just have to be assertive in making them. There's always gonna be someone who thinks they know better.