Hi! Lea!

The dungeons do get really long. I turned the puzzle speed down via the accessibility options are they were much more enjoyable, but I stopped at the same place as you for months/years before coming back and finishing it last year. I'm doing the dlc now but basically doing a puzzle or two and then leaving in for a day or two (now that I think about it, it may be a little longer since I lost picked it up...).