I am 21 years old, and I play volleyball for about 10 years. Semi-pro, but very intensive trainings, also at summer beach volley... What also might be good to say, since I was a child I could (and still can) jump very high about a meter vertically. A few months ago, I started to have back pain, in my lower spine, and horrible knee pain. I can still handle the back pain cause it stops after 30 minutes of training, and returnes after it (I don't care as long as I can play), but knee pain in my left knee is horrible. Yesterday I jumped and felt as like someone is stabbing me with a knife in my knee. I couldn't stand on my left leg for 10 minutes, and after that it still hurts a bit, but I can walk nicely today. The pain is at the top of my patella and inside, if it helps, I have uploaded a picture, to show where do I feel pain.
What do I do? please help!!!