I've asked similar questions and from what I've gathered, this is pretty normal in people with psychotic disorders. It's true for me as well, and I feel like the spelling like you have described has gotten significantly worse/very much like you describe, since being on meds. I've always had a bad memory and whether that has gotten worse with age/illness or because of treatment is debatable. My memory has had a fairly steady steep decline since pre-teens, the spelling definitely got way worse with medication. I wonder if it is similar to my art ability and the lack of ability to picture things in my head. I still know the basics/principles of art, but I can't picture them in my head now that we've found antipsychotics that work for me, I can just replicate or mix attributes of physical works. I use to be able to create in my head, or see the end result without having to sketch/draft it. Now I have to see a physically real visual. I wonder if without meds the words would come together in my head, except now, I'm left more with the basics/rules of grammar and spelling and have to physically see it to process.