When I felt lost, when my son was about 3, I read The Miracle Morning. It got me started on a morning ritual of reading, journaling and watercoloring before my son would wake up. It all went out the window with pregnancy fatigue, but I'm counting the days until baby finds her regular nap pattern and I can go back to waking early.
It's not a tangible, but I just started the ($5/mo) Momma Strong workout subscription. It's so great! When baby wakes up at 6:30, I make coffee, then head to her room with the laptop and yoga mat to do my 15min exercise of the day before my son wakes up. I'm only a week in but feel so much better lately.
May I suggest starting watercoloring? It's way easier than you'd think, and mid-range supplies aren't that expensive. YouTube has so many wonderful tutorials, especially the Let's Make Art channel. She's sweet and fun and explains things really well. It doesn't take long to feel like you're making progress.
Some paints: https://www.amazon.com/dp/B00004THXI?ref=ppx_pop_mob_ap_share
Brushes: https://www.amazon.com/dp/B01IQFDF98/ref=cm_sw_r_cp_apa_i_tWzlFbYW4XB7F
And paper: https://www.amazon.com/dp/B01G2IIZN2/ref=cm_sw_r_cp_apa_i_iXzlFb1J5MM4A
Do you journal? Interested in starting? I really enjoy having a nice fountain pen (also easier to use than I expected): https://www.amazon.com/dp/B015EXS130?ref=ppx_pop_mob_ap_share
Start with a cheaper gouache. Why pay crazy money for Schmincke for a medium you never tried before and you might, or might not like? I'd suggest the ArrtX 18-color set on Amazon for $18. It'll do what you need to learn and enjoy the process.
As for the brushes, they will be fine if you take care of them as you should. Brushes usually get destroyed easier with acrylic or acrylic gouache, but not so much with normal gouache.
Alternatively, you can buy this brush set on Amazon to use with gouache, if you're afraid about your expensive brushes: https://www.amazon.com/Grace-Water-Color-Brush-WS12/dp/B01IQFDF98 I mean, if you have the money to pay dear green Andrew Jacksons for Schmincke, you definitely have $7.50 for alternative brushes.