I'm sorry to hear you've been going through so much.

B12 deficiency can cause a lot of nasty stuff to happen. Glad they have you on the shots and it seems to be helping.

I have low blood sugar too. Keeping something whole grain or a bag of nuts with you helps with that. I used to keep a can of peanuts in my desk to help when I needed it.

MS is very much a DX of exclusion since there are a lot of things that can mimic it. My clinical presentation during the exams was not the norm, but my leisons were. It took back to back changes on the MRI and exams to get my DX. All my bloodwork came back normal, even the vitamin D test (which was not usual according to my neuro).

After a flare, some symptoms linger and can come and go like you're describing.

If it were me, and this is only my personal opinion - you know your bod the best- If the MRI was still normal, I'd give the shots a chance to see if that's what's going on. If it shows something this time, then I'd go for the spinal tap. Regardless, if anything gets worse I'd try to find a neuro who is very familar with or is a specialist with MS.

Hope things get better for ya.