Anyone else ever encounter this problem I'm having playing guitar?

Hi there, everyone. I hope some of you out there can offer some advice for me. I chose my "Name," pulpfriction, for a reason. You see, here's my strange problem in a nutshell: I'm 60 years old, a professional guitarist, and I play electric, acoustic steel string, and nylon string guitar. In the past couple years I lost over 100 lbs.,  as I needed to get healthy, all under the supervision of a doctor who is a weight loss specialist. All good, right? Not exactly. A weird side effect to this rapid weight loss, is that I lost the "pulp padding in the fingertips" of my left hand. Thus, when I fret the guitar, I experience great pain, as,  basically, there's no cushioning, if you will, in my fingertips, and the pressure on the tiny nerve endings in the fingertips is extremely painful. It's similar to what someone suffering from diabetes and dealing with peripheral neuropathy would experience.
  I have seen a neurologist, a pain specialist, two hand surgeons (one whose specialty is working with musician performance injuries), and am taking oral neuropathy medication, as well as applying a topical medication, augmenting my diet with nutritional supplements as per recommended - you name it. I have also consulted with the string expert at one of the major guitar string manufacturers to get their advice on customizing string sets, i.e., gauges, types of metal alloys that would best accommodate my situation, etc. But I still have pain - even after following the hand specialists' practice regimen on how to slowly work my way back, following a long period of rest.
  Basically, my question is this: HAS ANYONE EVER EXPERIENCED THIS, OR HEARD OF ANYONE WHO HAS EXPERIENCED THIS? OR HAVE ANY ADVICE THAT PERHAPS I HAVEN'T THOUGHT OF? MAYBE A LEAD ON A RESOURCE SOMEWHERE, WHERE I CAN SEEK ADDITIONAL MEDICAL OR PROFESSIONAL EXPERTISE? I would greatly appreciate it. And thanks for listening.