Is this a typical experience post weekly injections?

Hi all. I got diagnosed with b12 deficiency late May of this year. I went in for a routine check up, shared with my doctor that I had been experiencing atypical symptoms (debilitating exhaustion, random “lightning bolts” or “sparks” of sensations on the back of my leg—which I was told were nerve effects, etc.). They ran my tests and learned my b12 was deficient.

They prescribed me weekly injections of cyanocobalamin for 4 weeks, then 1 injection monthly for 3 months (with a check in later this month). The weekly injections helped so much. I finally felt able to go to feel more “alive” and alert.

It’s almost been two weeks without a weekly injection; my next isn’t until the end of this month. I felt super fatigued yesterday, but wrote it off as work exhaustion. Today I felt the tingles and lightning bolts in the back of my leg—the first time since my first injection. It started small then increased in coverage (further down my leg) and frequency.

If this has been your experience, is it typical to feel these side effects after moving from weekly to monthly injections and they’ll go away, or does this typically indicate that weekly injections are necessary? I hate the nerve tingles and the exhaustion was the worst; I’d hate to slip back into that level of deficiency.