I'm A Disabled Vet. I've Had This Numbness In My

i'm a disabled vet. I've had this numbness in my toes for at least a year now...my primary care dr. says it's because of my back injury from my military deployment many years ago...I am on the edge of type 2 diabetes and i told her it might be because of that...but i take metformin and the numbness is all day and all night more on my left foot than my right...can you help?