How To Cure Knee Pain?

I have been having pain in the knee for about 7 months. I finally went to the knee doctor and he said it might be a meniscus tear, so i had to get a MRI the following week. I haven't gotten my results back, but i'm nervous on what to expect. My knee hurts on the sides, all around the bottom, and in the back (behind my knee cap), but it's not continuous pain. I also have slight pain when i bend my knee (or sit cross-legged) or when i straighten it out. it also locks when i am walking down the stairs sometimes. So, what do you think I did to my knee?