Alright, i'm 17, and weigh about 300 pounds. I am OCD and take alot of medicine. I don't drink water that often. First my feet swelled up, then they went down, now my back hurts, around the kidney area, right flank pain, and sometimes left flank pain, and upper back pain, and when I get a pain in my back, I also feel a pain in my left at the same time. It hurts when I sit down and not that much when I move. If someone could tell me what you think is wrong, that would be great.