[mrsD]

No I don't think you need shots. If you are taking methylcobalamin? That is the active form.

You may be out of balance however with folate, or other nutrients. If you decide to take a folate, please choose methylfolate which is active too. Metafolin by Solgar is one brand. 800mcg a day is plenty for most people.

I'd try to stay on a fixed plan...say just one form of B12 daily at a regular dose, so your body can settle down and use it properly.
Say 5mg daily. Then get tested in 3 months, and do not take any for a week before the test. Injections flood the system suddenly and within 72 hrs that dose is gone. You can develop a see/saw phenomenon, with highs and lows, which you may be feeling.

B12 is not only one thing that works in the nervous system. Magnesium, folate, bcomplex and omega-3 fatty acids also do lots of jobs there.