--you should be taking B12 orally, anyway--everyday--a minimal dose of 1000mcg/day should be enough for you to passively absorb enough ( 1-2% of th dose) a bit so that you can stay up in level between shots, and possibly also begin to store a bit again.

You can also try a higher dosage (up to 5000mcg/day) to see if that would make you feel more optimal; some people get a little bit more hyper on the higher range doses but there is no known toxicity level for B12.

Many of us here take dosages in that range as a prevention, given the high requirements for B12 that damgaed nerves have. The methylcobalamin form is probably best--no need to convert the commercial cyanocobalamin preparations into methylcobalamin in the body if you can avoid it.

Most of all, it's a cheap way to keep up your level--I buy 3-month supplies (90 lozenges) for about $8 dollars through one of the many internet vitamin sites.