Pain, discharge, bleeding

I started getting a yellow creamy discharge w/ a sour odor in middle school. I never went to the doctors until last year because I was embarrassed even though I was still a virgin. I'm now 22yrs old, lost my virginity at 18. Last year my doctor said it's normal but I really don't think it is. Then I went to the hospital to have them check me too & they treated me for everything whether I had anything or not & they would call w/ my results but never did. They also told me it could be Pelvic Inflammatory Disease. When my boyfriend & I have sex it hurts like he is poking something inside of me. I bleed 8/10 times during & after as if I have my period. It lessens during the day & ends by the time I go to bed, but my boyfriend likes to have intercourse almost every day. I've been with him for 5 years. I know it's not his size so what could it be? I always think the worse scenario... Cancer :(