Knee pain on inner knee. Should i do?

I have been diagnosed with chondromalacia patella in one knee and was prescribed with medication and physiotherapy. I took medication for 2 months. Pain was a bit relaxed after medicine and there was some relaxation after physiotherapy. But now as i have stopped both, both of the knees started to have mild pain. It's not very severe but continuous. There is no significant swelling or redness. I am very much upset about the advancement as i am just 24 years old. I sit almost all of my daytime in office bending my knees. I am thinking about it most of my time. Is it reversible? Whether I should continue with physiotherapy/medicines or both? Please suggest. Should I walk or keep resting? There are controversial views from different online content. Can there be any other issue? What exactly should i do? Thanks in advance.