I had a blood test for b12 almost two months ago. It showed my b12 level was almost nonexistent.
I took 1,000 mcg sublingual b12 and it brought my level up to over 900 the high limit.
My dr told me to stop it.
A couple of weeks ago, I had it checked again and it dropped to 380, the lower limit.
Can this be why I am really tired, feel disconnected, moody, achy, have heart palpitations like extra beats and whooshing in my ears?
Now my dr said to go back on the 1,000 mcg of vitamin b12 for a month and then stay on 500.
I wonder if low b12 can cause all these symptoms.
I also have been trying to wean off estrogen.

Any help is appreciated.

Thanks