@Sandytoes You say mental health is more important than money, but don't forget being broke when an unexpected expense comes along or inflation makes a huge dent in your income will have an impact in mental health too.
I would worry about that and couldn't contemplate a life without holidays and the ability to buy what I fancy after a life of hard work. But, it 100% depends on your personal outlook, what really makes you happy and what you want your standard of living to be - just make sure you can cover the essentials and have money for emergencies.
Once you've given up work, it would be difficult, but not impossible, to boost your income again.
During lockdown, DH and I can live on about £1000-£1200 a month (no mortgage), but that's without annual bills, travelling or eating out and frankly, is miserable. I would hate to live like that every month.
Personally if I were you I'd carry on a while longer but, as I said upthread, perhaps change the type of work/reduce to part time.