I had that same exact problem as you. I played basketball all my life, in high school and such. My senior year during summer league and such I would get really bad pains right around my petella tendon in both knees. It ended up getting so bad that while i tried to play through it during the season, the next day after practice or games I wasnt able to walk up the stairs to my classes. I went to the doctors and they did an Xray and such and nothing was damanged but my Pattella tendon was very swollen. I took about a month off from playing basketball and went to physical therapy 3 days a week for about a month and a half. Since then I have been great. My suggestion would be to see a doctor to make sure you havent torn anything, and then just taking some time off and going to physical thereapy, trust me, it will do wonders! Its been 2 years since that has happend to me and I havent had any reaccuring instances. I bought 2 small braces for my knees that I wear when I play just as like a "safety" factor, but yeah, I would recommend taking some time off and some physical thereapy