Some Weird Knee Pain

hey guys, need some help. because im in the army and everything is going slow here so i want your opinion about what am im needed to do. ive got for 2 weeks already a knee injury in the right leg. after few days it went lighter but the pain is still there, i can walk up the stairs and squat normaly with bodyweight but the problem comes when the knee passes the finger line on the legs and then its a very sharp pain and it takes time untill it passes away but i cant fully recover. i used ibufen 400 mg for 3 days,a pill in the morning and before sleep but didnt notice a difference in the pain. what do you guys think it is and how can i recover faster?