I honestly don’t think there’s such a thing as too much structure. Routine = stability for me. Even though it is boring.
I agree with scheduling some ‘unscheduled’ time. This is what I’ve done:
Brainstorm some fun things
Write ideas on individual pieces of paper and fold.
Put papers into a container and pull out when you have unscheduled time.
My papers say things such as: do jigsaw puzzle, paint fingernails, shower using candles and nice soaps, paint by numbers, colouring in, weeding, sit outside and read a chapter of a book, watch a movie, knit 5 rows etc etc