Mean UK salary is £24k, so appreciate what you've got.
Median UK salary is about £18k, so MTFU.
Above £42k, you're in the top 10% of earners.
Money can buy self respect, and toys, and comfort, but it cannot buy happiness. In your case, I'd sign for the next 6 months, but save as much as possible / pay off my mortgage completely. I've worked in crap jobs before, but needed the money to pay the mortgage & bills. It's called life.
Sorry to roast you, but I don't think you appreciate how financially lucky you've been until now.
😕