So about a month ago I was playing soccer and my opponent crashed into me and I fell on my knee really hard. I didnt think much of it so I got up and when I started to run again I realized that I could barely bend or straighten my knee, it was completly numb, swolen, and I heard a pop/crack when I landed. The next day my entire knee was covered in a bruise, and was extremly sensitive. I couldnt even touch it softly without wincing in pain. The next day at practice I did'nt tell my coach because I thought I just bruised the bone, so while playing a game my knee locked and I fell on it yet again, but I convinced my mom that I was fine, so that I could continue playing soccer, and eventually the bruise went away, and the pain became dull, but recently I feel pain around my entire knee cap, and i feel a twitching/throbing pain coming from the top part of my knee randomly throughout the day. Also when I go up stairs sometimes my knee cap will feel like it is going to explode through my skin. Do you know what I might have done to my knee?