Intensive Foot Pain for 10 years

I have had major pain in my left foot for the last ten years. Maybe someone can help me reach a concluusion on how I should deal with the problem(s).
The first major problem is that I have a massive burning pain in my toe area that comes at infrequent intervals. I can somewhat help this pain by cracking my toe. The pain sometime migrates to an area just behind the large ball of the foot. I believe the toe cracking can somehow help pinpoint the source of this pain as there are others on this board with the same complain. The only way I can help the pain is to take 2-3 Ibuprofen. The pain will wake me out of a dead sleep. My doctor has ruled out gout and I have seen two podiatrist who were baffled by the cause. The other problem I have is that I have an area on the underside of the foot that is extremely sensitive to pressure and reacts with an intensive pain when pushed on. For example, I can walk on level ground with little pain, but if I walk on the beach amound of sand or a hidden rock will cause an immmediate sharp pain. I would welcome any ideas. As I said, I have been to two podiatrist who were unable to diagnose a solution. One injected a shot of cortisone that had abolutely no effect. Thanks to all,Carlos