Reading your post, the first thing I did think of was nutritional deficiency, possibly secondary to your alcohol consumption--though people do vary widely in the degree to which that would result in nutrient malabsorption. B12 deficiency, in particular, can result in very weird parasthetic nervous symptoms, both peripherally and through degeneration of the spinal cord. I'm glad you've been supplementing, but it might take a long time to repair damage (to the extent it can be repaired). You can also experience weird symptoms as nerves repair--and these are not usually distinguishable from those of worsening neuropathy except in long-term retrospect (many of us keep symptom diaries for comparison over months/years).

It's very possible the Prilosec contributed to this--we need stomach acid to break nutrients out of food, and you wouldn't be the first to have acid blockers result in malabsorption. We do produce less acid as we age, and this compounds the possibility.

But, then again, there may be other issues. And it does not sound as if you've had a really comprehensive work-up. Part of the problem is that symptoms of problems with the brain and spinal cord can be exactly mimicked by those of the peripheral nervous system, so investigations can be costly and time consuming.

Many of us use the Liza Jane spreadsheets (www.lizajane.org) to track our test results and to suggest more comprehesive testing to doctors--the spreadsheets were designed to include all tests for possible nerve-affecting conditions that a large number of us could think of--worth taking a look at, to compare with what you've had done.