Knee pain. What can be the problem. l?

Few days back it sarted paining in my both knee joints. I play football a bit but it was regular in last 3-4 months ,now I've stopped playing because of my knee pain. Because after that it started paining a quiet. It doesn't feel like muscle pain,or any problem in my bone,i fell like there is a problem in my ligaments. If i try to squats or any thing in which i need to bend my knees it hurts. I am not full aware about it but i think like there's a problem in my lateral and medial collateral ligaments. First i thought like i tore my anterior and posterior cruciate ligament but i gave a close look at my pain and i came to know that it was paining in the sides of my joints where collateral ligaments are present. Can anyone please tell me what can be the problem..l