I know you don’t want to start a new project but I think a bite-sized game jam like Neo-Twiny, Neo-Twiny Jam '24 - Submit for Charity!, might be useful. Design constraints with a tight turnaround means that you’re forced to move on fairly quickly.
Or… I find myself in a similar situation. I went back to a game I haven’t touched in almost two years and it was already very, very big. So, I’ve been editing it-- going back and reading it for style and typos. That’s been a useful way for refamiliarizing myself with variables and other logic, as well as the narrative itself. Plus, it’s a productive use of my time as that’s something I needed to do on the project anyway.