Mononeuritis Multiplex Help

I am a 66 year old male and have had mononeuritis multiplex since a bout of necrotizing vasculitis six years ago. I developed plantar fasciitis 18 months ago and the combination of the two ailments makes it very painful to walk or stand.  Do these two ailments go together often?

The neuropathy pain was bothersome but bearable on 1200 mg./day of neurontin for almost five years. Since the plantar fasciitis became apparent the pain has become much worse and I am now taking 3600 mg./day of neurontin and the pain just gets worse.  My podiatrist can't do anything for the plantar fasciitis although I've tried all the standard stuff (stretching, cortisone shots, orthodics, telling me to take ibuprophen, etc.) and my local neurologist just says to take more neurontin and add some tramadol.  Is there anything else I can do?

Thanks.

Augie42