B12 levels dropping. Could be Pernicious Anaemia?

Hello there. I had an endoscopy before Christmas as a follow up as I was diagnosed with Celiac disease a couple of years ago. The report said that I have generalised atrophic gastric mucosa, mainly at antrum. My GP asked for a B12 test which came back at 275ng/L which was said to be normal however, this has dropped from 476ng/L in just over a year. I am also folate deficient now at 1.5 ug/L. I am awaiting results from the biophys that they took.

I have no B12 symptoms apart from pale coloured stools and a churning stomach.

I suspect that I might have pernicious anemia. I have ordered a private PA test which includes IFAB and MMA.

Where do i go from here? I am terrified that my B12 levels are going to drop further and start causing irreversible neurological problems.

Thanks.