Ovarian cysts cause disturbances of FSH/LH ration leading to hormonal imbalance which causes absence of periods or cycle length more than 32 days. This also causes scanty menses like you are having. There are no permanent cure of ovarian cysts but it can be manged by laparoscopic diathermy which is a type of surgery. But this can reoccur after 2-3 months. So, if you are wiling to get pregnant then get this surgery otherwise no need.