There can be several reasons of your generalized body numbness although without being able to examine you I can not offer you the specific advice on diagnosis and treatment that you need, but I would try to provide you some relevant information about your health concern.
Most likely your symptoms could be due to circulatory problems (due to low blood pressure), injury to a nerve, pressure on spinal or peripheral nerves (neuropathy), vitamin deficiency, viral infection and use of certain medications. In addition, atherosclerosis can also cause pain, numbness, and tingling while walking and they can also reduce blood supply and lead to numbness. Please consult your doctor to get all these possibilities evaluation in your case for further assessment. Hope this helps.