What Causes Feet Numbness And Pain With Tingling And Burning Sensations?

I have had numbness and pain in my feet for almost a year. I first thought the tingling and burning was a fungus thing but after a time numbness set in.I woke today to discover a large numb patch between my left knee and hip. My job often requires me to stand up 12 to 14 hours a day. Any thoughts?