Pain in the lower leg radiating to ankle. No relief after taking ibuprofen and aleve. Not able to walk. Overweight

Hello Doctor,

For the past several weeks, I've had pain in my lower left leg. The pain would float: under my knee, down my outer shin, around my inner ankle. A dull ache persisted on the outside of my leg a few inches below my knee; it did not respond to Aleve or ibuprofen. Ice and heat also seemed to have little response. I walked with some discomfort, but without a limp on even ground, though I struggled up and down stairs.

Yesterday, I decided to go for a stroll. I walked about 2 miles, developed a limp, then finally heard a pop. I lost balance and almost went down, but caught my balance. I leaned on a tree to hold myself up and grabbed a cab home. Now, whenever I put pressure on my left leg, the pain is very sharp a few inches below the knee and my leg feels weak. I have to hobble inch by inch to move around my apt. To look at things, my left knee looks just like my right: there is no discernible swelling, but my left leg is useless. I can't walk on it.

Ice seems to alleviate pain somewhat, but there is little to no swelling to shrink. I have a history of crepitus in both knees, and my left knee has always had problems. I've always had to extend it after a while to alleviate pain. I've also had trouble getting up from seats on buses, for instance, using my upper body more than my lower body to lift myself up.

My main concern is that too much pressure is now being placed on my right knee to the point of potential overload. At 350 pounds, I'm a heavy man. I can't imagine having two inoperable legs.

What do you feel is my problem and the best way to go about diagnosis/treatment.

Thanks,
Zach