I retired 2 years ago. I'll never work another fiat job again if I can help it.
I've spent a good portion (maybe 18 months) mourning my old career & exploring what excites me. It's not that I don't want to work, its that I don't want to be a fiat slave anymore.
You definitely need to find a new purpose & a reason to get up in the morning.
These days I'm up before 4am & don't set an alarm. My days are filled with productive work on my land.
What I'm realizing is that completed projects are far less satisfying when they're completed solo & for myself.