It was very much like that (except I had stabbing pains, burning soles, muscle cramps, the feeling like someone was squeezing off my big toes with a nut cracker, and rocks under my feet as well).
The first time I quit I relapsed after 45 days because the pain came back worse than ever.
The second time (this one) I did manage to stay the course, but the pain - as documented in the PN subforum - came back and became worse & worse for the first 8 months. Oh joy...
Like you, I have long searched for other reasons apart from the alcohol (can you say "co-morbid"? ...), and I guess there were. Low B12 may have also be caused by taking antacids (Pariet) for years on end - it's a known side effect.
But.
In the end, I realized that everything had one primal cause: stress. I was doing too much, working too hard, and that set of a lot of things like reflux, drinking, anxiety, hyperventilation, and then some. And they all nicely enforced each other.
I'm not saying that as an excuse, because I have no doubt when it comes to the PN, it was mostly if not exclusively the alcohol. Put another way; I wouldn't be where I am today (yesterday I knocked down a brick wall, today I'm doing drywall and electricity) if I hadn't stopped drinking. I could also be slightly dead by now.
So yeah, it is a tedious process, often disappointing, and it never hurts to check all factors that can contribute to your PN, but, if you find something, don't let it fool you/trick you in trying to become a "moderate drinker" etc. You, me, Icehouce, we passed that station IMHO.
You'll get there, hang on.