It sounds like you have peripheral neuropathy. You may not have circulatory problems, but there is certainly something blocking proper neurological messaging in your feet. Do you have diabetes? If you aren't diagnosed or haven't been tested recently, check into it. Because it is both feet, that is the first thing I can think of. Have you recently changed jobs where you sit more or are you using a new chair? Pressure may be being applied to the back of your legs in just such a way that it is putting pressure on the same nerves and may add to the problem. You really need to see your doctor and get some testing done very soon. Good luck and good health.