I am probably going to get downvoted into oblivion despite just sharing my lived experience, but I felt kind of similar to this on a smaller time scale for a couple days after my first and second pfizer doses. I would, at random times, have ZERO recollection of what I did in the time window starting ~20 minutes ago and ending ~20 seconds ago. Like, questioning whether my phone was stolen because there were photos in my camera roll that I was positive I had never seen before. I saw my GP about it and they suggested 8 hours of sleep with a regular schedule (I do), making sure I take a multivitamin (I do), making sure I'm getting adequate nutrition (I do), and to come back in a week if it was still happening.

Mine luckily cleared up after a few days, but I got it again the day after I got my 2nd dose, which also fortunately cleared up after a few days. Got Moderna for my booster and did not experience that with Moderna at all. I'm starting to wonder if I got unlucky and just got 2 bad batches from Pfizer or if it was possibly psychosomatic / stress-originating rather than chemical/biological.

One suggestion I have, something that helped me feel a lot more comfortable and secure in the world was asking family / close friends if they had noticed changes with me lately, and leaning on them to help me reconstruct a timeline of when it started happening. I hope that can offer assistance to you, but definitely see a doctor (or multiple doctors, if you are unsatisfied with the treatment, or want further confirmation of the diagnosis / other ideas) too if you haven't already.