fyi, this can happen in a successful startup/business also. this happened to me when i was stressed out of my mind and stuck doing work i hate for customers i didn't want after 10 years of running a biz.

it took a breakup, a sale of the business, and nearly 2 years of doing nothing until i recovered.

fwiw, the biggest takeaways the whole thing taught me are 1. be careful of what you wish for and 2. both attractive women and customers want outcomes, they don't give a shit about your problems and 3. never forego vacations/holidays for work.

as for me, well - you know how the saying goes - it's always darkest before the dawn, and life is good now. for the time being. but i know that if i wake up one day and i'm feeling like a fucking pack mule for people who don't appreciate me, it's time for a massive rapid change, without the period of suffering this time.