Thumbs up on the lion's mane. Works for me as long as I remember to take it properly.
I see you're taking B6 but not sure which form it is. But you should know that one of the reasons B6 has some small application in the treatment of neuropathy is because of how it enables thiamine to do its job.
You are taking benfotiamine but I don't know the dosage. Whatever you are doing with it, do what you can to ensure you are taking a minimum of 400 mg thiamine daily or its benfotiamine equivalent. Also match that B1 dose to riboflavin. 400 mg riboflavin but don't slam your body with that much all at the same time, stagger the doses during the day.
Make sure the active cobalamin you are taking contains at least some adenosylcobalamin. If you are taking only methylcobalamin then you are missing out. The body can convert adenosylcobalamin to methylcobalamin but not the other way around. You need both forms of cobalamin; they have different jobs inside the cell.
The only catch about all of this is taking high doses of lone B vitamins for an extended period of time while neglecting to take the other B vitamins. I suggest you find an active B-complex to add to your regimen, and one that includes sufficient doses of pantethine (most active B complexes like to skimp on this) or getting the pantethine by itself. Especially since we are talking about assisting total cellular function.
I have read studies where memantine was successfully applied in the regeneration of nerves from crush injuries, albeit in rats.
I also have seen in the medical literature that taurine is beginning to be investigated for application in nerve regeneration, including numbness. Some studies in animals showed that taurine had no effect, and others indicated some efficacy. I can't recall more specifics than that but I do remember that they were studying different kinds of nerve damage, and using different species of test animals, so that may have been a factor in the mixed results. I suspect that taurine alone would be ineffective as it would be like taking just one B vitamin by itself - if there is any application for taurine in this kind of thing, then it would be in conjunction with other supplements.
It is probably relevant to know exactly what nerves have been damaged.