Hello I understand your concern. Burning feet can be mainly due to diabetic neuropathy but the blood work already suggests absence of diabetes.Next possibilty can be Vitamin B12 deficiency/peripheral artery disease/hypothyroidism/alcohol abuse.These all cause peripheral neuropathy resulting in burning feet You didnot mention your gender.It could have given some clue. I advice you to do certain investigations like serum Vit B 12 level,thyroid tests. If the burning sensation comes on walking,Doppler scan of blood flow in legs will be required. Specific treatment depends upon the cause. You may talk with your physician regarding all this. Over the counter meducations like advil once a day for 5 days or tramadol may help relieve the sensation. If still the problem persists,you may visit neurologist.Certain nerve tests may be advised.Anticonvulsant drugs like carbamezapine or gabapentin may be started. Hope this information helps. Thanks