You're probably OK without b12, especially if you eat red meat. Vit D is so inexpensive, and since you were low according to the tests, I'd stick to that one.

I am personally gibing the benfotiamine a shot. Here in Canada its not sold in stores so I went to I herb.com and ordered some. Its helpful to read the user reviews.

All of these take time , more than one bottle. Its tough, because we want results right away.
Alpha Lipoic Acid is a big one that is used with success, especially for diabetics. It ha some blood sugar lowering effects. I used to work at a health food store as the nutritionist.

As for medication, I have found that a combo of Lyrica and opiates to be what get me through the day..
Good luck