@deanbiglets
Hi Dean, welcome to Connect! You are the second one that I know of who said their peripheral neuropathy (PN) was caused by a low b12 level. Another member, @rwinney also developed near crippling neuropathy in many parts of her body (feet included) and is totally convinced ( as was her doctor) that low b12 put her in that condition. I have confirmed through some online research whereby other websites mention b12 as a possible cause of PN, so obviously a number of people are in that category. As far as the muscle issues you are experiencing, I do know that quite a few people here swear by Myofascial release, have you heard of it? There is a discussion here that addresses it that you might look at:
https://connect.mayoclinic.org/discussion/myofascial-release-therapy-mfr-for-treating-compression-and-pain/?utm_campaign=search
This might be helpful to you, for both your feet and you knee issues.

Regarding medications, there seems to be a pattern I have noticed that physicians rely on which include gabapentin, Lyrica (pregabalin) and Cymbalta (duloxetine). Some people are helped by one of these, many are not. Many people after trying these unsuccessfully (like my wife) move on to a variety of relaxants and stimulants such as THC based marijuana or cannabis oil as well as kratom, ketamine, etc. You may eventually decided to explore one of these if you find nothing else for relief of your pain. I do hope you are able to find a way to cope with your pain so you can continue to lead a normal life. Unfortunately, my wife's PN in her feet/ankles (since 2014 from chemo) has reduced her world considerably, a very sad state of affairs. Best, Hank

Hi Dean @deanbiglets, I would like to add my welcome to Connect along with @jesfactsmon and other members. I was told by my neurologist that there were no medications that help numbness from neuropathy. Before I was diagnosed by a Mayo neurologist, my primary care doctor prescribed Gabapentin and I took it for a few weeks with no difference before I stopped taking it and had the appointment with the neurologist. I'm 77 and also have some balance issues when I walk. I've found using trekking poles or Nordic walking poles allow me to walk and help with my balance. If you love to walk and it helps you feel better, you might want to give them a try.

Nordic Walking vs. Trekking Poles - What's the Difference?

@helenholland3
@deanbiglets
@larrymc
@jesfactsmon
Like Hank mentioned seizure meds can cause it too. That's what happened to me. i’ve had neuropathy about 40 years. I went through all the horrendous pains of every sort and could barely walk. But my awful pains eventually went away. However the numbness never did go away it went from the bottom of my feet up to my waist. The lower it is the worse it is. I never found anything that could relieve my numbness. My doctor put me on fentanyl for other pain which had a beneficial affect on the neuropathy pains but not the numbness. I went up to 3600 mg, the maximum dose of Neurontin. It had no effect on my seizures or neuropathy. I knew of a patient who was taking 7000 mg of gabapentin but I don’t remember if he had any beneficial results. I wouldn’t think he would take that much medication if he didn’t help him. Like John I too have balance issues primarily from seizure medications and I do fall quite a bit but that’s primarily due to the fact that I have difficulty with numbness so I end up tripping myself.
Best wishes,
Jake