I sprained my ankle about 5 months ago, I was just running &fell on it wrong. I stayed off it for about 2 days, and it stayed wrapped &i iced it a lot. Then I went back to school. My ankle eventually stopped hurting but now it hurts if I move it the wrong way or if I cross my legs &sit on it. It hurts when I start running. It's a little more fatter than my other ankle. The left one looks fine but the hurt one is fatter &you can see it. I never went to a doctor &my parents say I will be fine. What should I do? Should I go to a doctor?

You do need to see a doctor. The longer you wait to receive proper treatment the greater your chances of causing permanent damage are.