Pain during sex

Okay so I've recently experienced pain during sex, or maybe I'm just now noticing it.... Well anyways the area around my vaginal opening is very sensitive when I clean myself and has been for a few weeks now.... Occasionally I'll have a pulsing type feeling down in that area but I just tried to ignore it. I was told that I had a cyst on my left ovary in December of last year and was given birth control to help manage it. I'm really freaking out because I think I may have endometriosis after doing some reading. I'm only 21 :/ help