I know that endometrial hyperplasia can occur due to things like obesity, PCOS, or tumors in the uterus, among other things. As long as you had just endometrial hyperplasia and not atypical endometrial hyperplasia, your chance of developing any sort of cancer from it is really really low (less than 2%, and I think for you it's pretty nonexistant, since yours wasn't caused by an ongoing condition). Atypical endometrial hyperplasia comes with about a 22% chance of developing cancer at a later date.
Treatment can vary based on the severity and the individual. It could be something as simple as putting you on hormone therapy (which is what it sounds like your doctor is going to do), all the way up to a hysterectomy.
From what you told us, it sounds like you're going to be a-ok in a few months! Your doctor will probably be keeping a close eye on you during that time to make sure that things are progressing appropriately, and that nothing bad is developing. The fact that your endometrial hyperplasia was caused by an ectopic and not an ongoing condition is a good sign for full recovery, I think!