Talk to Gynecologist on Pain In Leg Joints And Right Side Of Backbone

I am 29 years old mother of a baby boy 6months old. before my delivery I was fit active and had no issues. but after the delivery (C-section). I came across many problems my feet use to swell upon consultation I cam to know that I have a cholesterol issue and now that issue is resolved . but now I feel too much pain in my both knees and around backbone specially when I feed my kid. is it due to weekness or what. I don't know what should I do please recommend some medicines or exercise + I am working lady. thanks