Back and Knee pain. What should i do?

I'm feeling pain in both of the knees while raising myself up in any form. Be it using Indian toilet, stairs or any kind of exercise requiring me to raise myself from a squatting position. Apart from it I feel pain while crossing my legs as well. My left knee pains more than my right one. It seems like some nerve/vain from the end of my spine at the waist, running through the side of my left knee, going all the way down to my left ankle is stuck somewhere and is paining in addition to the knee pain itself. My lower back specifically the end of my spine along with my knees are not able to bear any load it seems. I'm overweight and am trying to reduce by walking and playing badminton as of now. What should I do? I live in wada which don't have specialised medical facilities, and I can only travel on weekends when most of the clinics are shut. I would appreciate of any of the specialists here can comment on it so that I can at least prepare the necessary reports and x-ray before visitin