sharp stabbing pain in the lower right side of my back

I have had a series of issues. The first was that I had rectal bleeding, and I went to the doctor to check it out and she gave me hemroid cream. Well it didn't stop and I have filled the toilet bowl twice since with blood. I also have not had my period for 3 months and I know I'm not pregnant. Lastly, I have a sharp stabbing pain in the lower right side of my back, right above my hip bone. The pain comes and goes, but it hurts most when I am still (sitting or laying down). When I am moving around or active I feel fine. The pain also travels down my leg and hurts different places like my knee, calf, and foot on the medial side. I can't sleep at night because the pain is so bad. Also, I have had pelvic pressure and pain and have noticed frequent feeling of urination. I have had a UTI before and know that it is not a UTI. The pelvic pain becomes increasingly painful when I am about to go to the bathroom. (number 2) I am 21 years old, very healthy and fit and I don't want to be in pain!