I completely understand your frustration and am sorry you're still struggling.
While I can't speak to protocols other than Buhner and Cowden, I can tell you that Buhner advises treating for a year.
And, I'm not sure what you were treating for but, I've become more and more inclined to suggest that people consider herbal protocols that address both Babesia and Bartonella.
I say this because my research shows that people can be dealing with asymptomatic Babesia and/or Bartonella infections which can impede their healing from Lyme if those other infections aren't addressed.
Your story sounds familiar to me because I, too, could not shake the peripheral neuropathy I developed on abx despite almost 6 months on Cowden (and a decent amount of herxing).
I was/am taking increasing numbers of different supplements and now also herbs in the hopes of kissing peripheral neuropathy goodbye.
What has really made a difference for me was my decision to treat for Babesia....even though my LLMD never thought I had it and still doesn't.
However, I herxed with many symptoms that overlap between Lyme and Babesia....and I wasn't healing. What did I have to lose? My LLMD supported my experiment and I'm a little over two months into it and still titrating the doses of the herbs.
I am thrilled to report that I'm finally experiencing improvements....and I want those improvements to eventually bring me to complete relief of symptoms.
I'm tired of wasting time and money on treatment so I'm also herbally treating bart....I figure I'll try to knock them all off at the same time lol
Another thing that comes to mind for your situation is the fact that you didn't mention anything about
detoxing. Do you have an established detox protocol?
If you're not detoxing, you really should be.....and if you are detoxing, you might want to consider adding a few things and continue to add things.
Detoxing helps get all those dead bug parts and toxins they create out of the body. If we don't help usher that stuff out, it can be reabsorbed into our tissues and cause problems (symptoms).
The site I'm linking below is in the "New to Lyme" thread but I share it often because it has quite the comprehensive list of detox suggestions:
www.tiredoflyme.com/detox-methods.html Without a doubt and if you are willing, please share the various protocols you've followed including what you were taking and for how long.
We have a wonderful group of knowledgeable members who will gladly help. Full healing might be closer than you think if you get headed in the right direction.