Can't get rid of hand pain

Hi everybody! I've been treating my B12 deficiency for about 3 months now, but I cannot get rid of my hand pain. While I did have other symptoms such as inability to concentrate, fatigue, depression, dizziness, etc., my main issue was pins and needles in my hands as well as pain in my elbows and in my forearms. The pain generally just feels like muscle stiffness and weakness, and it's very hard to use my hands.

When I first started treatment just with sublingual liquid B12, my other symptoms went away but my hand pain stayed. Then I started getting weekly injections from a medical spa, and the hand pain went away completely. My hand pain would come back after the shot wore off either 2 or 3 days later, and then the shots eventually stopped working on their own. Then I started getting better with cofactors and it seemed to get better for a little bit. But then I started injecting on my own more frequently and it started to come back.

My most recent thought was that my folate was too low, as I was taking around 1 mg a day so I increased it to 5 mg gradually over the last several days. Sometimes my symptoms will go away if I take more folate and sometimes they won't. I truly don't know what else to try at this point.

My current regimen is as follows: - EOD injections, 1250 micrograms methylcobalamin - 5 mg methylfolate daily (I just titrated my way up to 5 mg over the past couple weeks) - 5,000 IUS D3 every 3 days (my vitamin D levels were actually on the high end when I had them tested) - multivitamin every other day with all B complex vitamins and trace minerals - B complex every other day alternating with the multivitamin - electrolytes three times a day (Dr. Berg mix)

Also just to add, I was tested for B12 before I started this. My initial level was 286, and my folate was 6.4. When I was tested my iron levels were good, although I probably will have them tested again soon. Like many people, because my levels weren't "low enough", my doctor wasn't able to help me.

Is there anyone else out there who has had this problem? What did you do to fix it? I'm so upset about this because I need to use my hands for work and I haven't been able to do any of my hobbies. I'm sick of laying around and watching TV. It seriously depressing and disheartening as I have career goals that I cannot go after at this time because I literally can't use my hands.

Please excuse any typos. I have to use voice commands to type out messages now. Thank you in advance for anyone who was able to help!

ETA: I also had MRIs done on both elbows and nerve conduction studies done on both sides, from elbow to fingers. Both came back normal with no abnormalities noted.

I'm also unable to eat folate rich foods due to dietary issues. I'm not totally sure at this time, but blood markers show that there's a possibility I have IBD. I will also be seeking further testing for this.