@Bunniekins Sorry for the late reply I have been having some issues lately. As for your concerns with the memory issues there are a few things that can make that happen. (Aside from the mental illness itself)
1.sleep problems
2. Age
3. Mental overload
as for medications there is some evidence to suggest they can have an impact on memory but not a lot has been studied in that regard of the ones I can remember reading about there was issues with loss/reduction in grey matter with long term use of antipsychotics and a correlation between antipsychotics and long term use and increased risk of like dementia type stuff but there was nothing conclusive and it is hard to find control groups for such studies.
I am sorry you are so trapped in this situation it really frustrates me that doctors often don’t listen to their patients in regards to meds even if it works in some way you shouldn’t have to put up with such shitty side effects.