Hi- 22 Year Old Female. Tender To Touch And A

Hi- 22 year old female. Tender to touch and a small bruise at fibular head on left leg. Knee feels a lot of pressure in left anterior, left posterior, and left lateral part of the knee. Knee also feels full, thick, and some pain to flex, but also feels painful to fully extend. Feels pressure and pain on left lateral side of knee when standing and bearing weight. I have iced it twice today (~10-20min), but ice hasn't helped much. Any reasons to what injury this might be? No rememberance of hitting my knee anywhere. I am an active individual and on my feet a lot (~8hrs).