I'd like to suggest two things:

1) get the test results for the B12... lab ranges go down very low and labs continue to report the low values as "normal"... some doctors (but not all doctors) know now to go by the numbers, not the ranges.
You should be at least at 400pg/ml or above. If below that then you need to supplement with active methylcobalamin daily.

2) this is pretty obvious, but are you on a statin for cholesterol?
Statins raise CPK.