shouldn't this be getting better by now?

as most of you know (and if you don't just read back through some of my old threads) my b12 is EXTREMELY low right now and i've had to start getting b12 injections once a week for 4 weeks and then once a month thereafter.

so i've gotten 3 shots so far and i'm a little bit confused about this. the nurse that i spoke with at my pcp's office said that i probably was having difficulty thinking and remembering things and expressing myself due to having such a low b12 level. and YES, this is ABSOLUTELY TRUE!!! but she said that i'd start feeling much better and more like myself after just the first shot.

well like i said before i've had 3 shots so far and it seems like my mental capacity is diminishing with each shot instead of improving. (and no, this isn't just a hypochondriac moment either. my girlfriend even made the comment yesterday that she's noticed my speech and memory getting MUCH worse here lately.)

i wonder why that is. does anybody here have any insight into this? i'm going to ask the nurse when i go in for my 4th shot next week but i wondered if anyone had any suggestions about possibilities that i could be researching in the meantime.

thanks in advance for any advice or suggestions that anybody may have