Suggest Treatment For Pain In My Knee

I have got an injury at the side of knee around the hipped mass while exercising in gym 1 month back. I ignored for 1 week thinking that this could be exercise related pain. But then consulted a physiotherapist who suggested application of ice and hot water bag alternatively for 1 minute each. Now the swelling is very negligible and there is no hard pain at the site of the injury, but I can feel stiffness and pain all the day at other parts of my leg - lower and upper thigh and lower leg including foot. Please advise what should I do.

Thanks,

Prasanta

Male, Age, 32, Height 161 cms, weight 77 K.G