Problems with my knee, what should i do?

I think you answered your own question that little weight you mentioned probably would make a difference and eat jello cause its fat free and contains glucosimine which is recommended for healthy joints

Sounds like you have the tendon for the kneecap shorten up on you. When that happens it pulls the kneecap up on and into your knee making it hard and painful to bend your knee. You can release that tendon by yourself but you have to make sure that you put a lot of pressure on the leg when you are doing this or it won't take. If that happens repeat it right away. Here is how to release your tendon for your kneecap:

Kneecaps:

Do while sitting on a chair with no front cross braces.

While sitting have your leg resting in a stretched mode. Place both your thumbs, side by side, about 2 inches behind the kneecap and press down into your leg and then redirect the pressure a little towards the kneecap. After 30 seconds, slowly slide your foot back and under your chair as far as it will go, release the pressure but hold your foot there for another 30 seconds.

Well first stay off that knee. You say your a little bit over weight so I don't think your heavy enough that you are causing joint pain. Perhaps you twisted it earlier but did not notice. Hard to tell. Stay off it for a bit, perhaps get some crutches. If it doesn't get any better in 3 days, go see a doc so he can look at it.