Hi there. How old are you? My son runs on his high school team and my other son runs XC on his middle school team. Both are quite serious about it and strive to be one of those top 7 varsity guys! Only ONE knee hurts? Which part of your knee hurts? Front, back or sides of knee cap? It only hurts WHILE you run? What is the end result when you are done? Shaking after you run is not uncommon and is usually a sign you were running on empty during your practice. It's the after affect of that. Lactic acid builds up. Do you do anything for recovery? My son's coach instructs them to drink a bottle of chocolate milk for recovery post run. You could have a protein shake or smoothing as well.
So, does your high school or college or wherever your cross country team is from have a trainer? They are a really great resource. You may have what is called runner's knee. The recommendations for runner's knee are to rest. That's hard for a runner. But also if you can't just flat out take a break, do pain free running. If sprinting hurts it, don't sprint. If you can only run for 20 minutes at a fast clip without pain, do that. When you have pain like that, you probably have inflammation and a remedy for that is simply taking ibuprofen. It will decrease internal swelling. So, you could try it before you run if you are having a training session that you know will require sprinting. They call look at all sorts of other things like the shoes you wear, how your muscles are strength wise and how you strike your foot. That is all super technical in my opinion. But if you have a trainer and a good running shoe store, you can get some great advice. If this becomes chronic, you should see an orthopedic doctor for guidance. good luck and happy racing!