How big is your cyst? Sometimes they take more than 3 months to go away. Is pelvic pain the reason they suspect endometriosis (endo)? I assume you know there is no cure so even if you have surgery, it will likely give you only some temporary relief. As far as the post-op recovery period, I cannot answer that as I have no personal experience. It does seem somewhat individual by surgeon and patient. And some surgeons are more optimistic than others as far as risks and recovery.
I went back to school a week after my surgery. You likely won't be in much pain, but will be very sore and quite weak.