My opinion, again:

Continuing cyanocobalamin injections if you cannot convert them, to active form (this is a genetic error that is not rare)... will
not work over time. The injections are not an active form of B12 unless you are getting them especially compounded from a compounding pharmacy.

That is why using oral active methyl form on an empty stomach is
much better in the long run and FASTER for you.

But it is your decision anyway.

You don't need injections AT ALL... please read this: Written especially for doctors, but understandable for laymen too:
http://www.aafp.org/afp/2003/0301/p979.html

Estimates today are about 10% of patients have DNA failures called MTHFR errors. A doctor came on here not too long ago and said at a conference he attended recently they raised that estimate to up to 30%.
If this is your problem, you'll have to have testing (DNA) done to reveal methylation failures, or always use the active form which bypasses this error= methylcobalamin.

But if you like injections of cyanocobalamin, that is your choice too. We only offer options that are medically newer and accepted, than most doctors are aware of.