Thanks for writing your query.
Based on your description it seems you have osteoarthritis
knee. My advice would be do hamstrings and quadriceps muscle strengthening exercises,avoid squatting and cross leg sitting.Beside ibuprofen
as pain killer you may take glucosamine
,the recommended dose of glucosamine sulphate (1500mg) and chondroitin sulphate (800-1200mg) daily in divides doses. Glucosamine by nutralite is a good brand and with balanced composition. This is usually given for 3 months and then 6 months off after there is symptomatic improvement. This is not a pain killer so additional medicines are required for pain control and optimum joint activity.
Regarding exercise avoid jumping/jogging on hard concrete surface, swimming is the best exercise.
Avoid food which is rich in sugar, oil to control body weight and eat food (whole grain, fruit and vegetable) which are rich in fiber.
I hope this information suffices.
Dr.mukesh chugh (http://bit.ly/drmchugh)