Hey there @Violacorso, I also live with schizoaffective disorder. My episodes can also come on quickly and are often linked to my other medical issues (I have thyroid disease and that can trigger a depression or manic episode). As for the psychotic part of things, they can also come on quickly too (an early warning sign is an 'electrified' feeling in my body along with not sleeping and being extremely paranoid). Unless I have treatment for my hallucinations, paranoia and delusions (psychology, psychiatry), they continue unabated. I am lucky to have struck upon a combination of medication which seemingly does the best job possible to keep me well.
I've had numerous hospitalisations over the years since my first episode. I don't know if I'll ever be completely free of bad episodes, but I do know they are getting fewer and fewer between and not as long as they once were. I guess it does get better with time.