CrimeofPassion, if you have cyano B12, try to get your hands on some methyl B12 sublinguals instead. However, within 3 days of taking B12 (and I have symptoms similar to yours), the tingling went away, so it should be ok for the short term.

I take B12 in the morning about an hour before breakfast, but because you aren't swallowing the pill, and are instead letting it get into your bloodstream through the gums, tongue and cheeks, then it shouldn't matter too much if you take it with food, as long as you try to let it dissolve as slowly as possible. Healing with B12 takes time.

A good quality fish oil is best, but whatever you can afford really. Perhaps others will have suggestions of brands for you.

Anything that makes you feel better is a good thing, such as menthol balm, socks, massages etc. But you really want to find out whether your body is lacking in something. You might be low in iron too, like me.

It's up to you whether you want to test for B12. All you can do is ask. Try to get tested before taking supplements, otherwise the test result will be artificially inflated and not a true representation. All of us here have had the brush off from one or many doctors in our quest to get better, so if it happens to you, you're in company. A lot of drs have no clue about it. If I followed their advice, I'd still be lying in bed resting my arms all day.