Long term use of dienigest. Be continue?

I am a patient of endometriosis on both ovaries. As I research many Papers on various site & understood one thing that Endometriosis has no cure, it can be suppresed by medication otherwise needed surgery if cyst size greater than 5 CM or other parameters by usg. And also study that Multiple times of surgery Decreases ovarian reserve and it causes more fertility issue in future. So I don't want to Go for surgery at least for 2-3 years, as I want to do surgery only before my conception if needed. My cyst size is also 3 CM & 2 CM. So I want to continue dienogest 2 mg which is works on me & it vanished all my pain. So i want to continue long term use of dienogest 2mg. All ready I used it 2 years and then give a gap of 3 months and again starts for 3 months on going by my doctor. But my doctor told me that do a surgery, because full cyst will not be vanished by this medicine. What should I do? [ I  will marriage after 2 years. ] How long years dienogest 2mg can be continue?