PHs in Zim said they had to keep their shins "hardened" by constant walking in the high grass, etc.
Concerning the OP questions may I give a bit of advice--first, don't concede to neuropathy--push the issue to get in shape both for any upcoming hunt and for your healthy future. Incrementally walk farther, no matter what. Second, consider that there are other hazards in just getting to Africa. On my first flight to Joburg, an elderly woman (you do not qualify as elderly in my book) almost died ON THE FLIGHT! If someone had not had an oxygen bottle, the type of which mountain climbers carry with them, I feel pretty sure she would not have made it. And when the crisis came the plane was 800+ miles equidistant from any land and hence landing site. I heard the captain tell her "Ma'am, you have to make it." You have to also be healthy enough to reach Africa, after all. Not trying to be unfeeling, just a little tough love maybe for your own good. Hope you overcome all obstacles and have a GREAT hunt.
It's a pity that we so often can only afford to go when we are older, but then, the safari industry is well accustomed to accommodating that. Good luck and God bless.