@Lupin61
I've mainly read your posts and not posters' so my apologies if you've already received advice I'm about to give you.
In your place I'd quietly start getting organised and seeing a family law solicitor to see how you'd be situated when you divorce. So market price/equity on your house, both your pensions, savings in all your accounts. Look at properties to see what you can afford to buy once you've split. Ensure you have your own bank accounts he has no access to and your salary should go there, with you transferring enough to a joint account, if you have one, for bills.
Transfer half of any joint savings into your own, solely held bank accounts, so he's unable to drain those accounts. Don't think leaving you without money isn't something he'd never think of, once the relationship sours.
Move into another bedroom and start leaving him to do his own personal admin (car tax, insurance, laundry, etc) because he'd be doing that if you weren't around wouldn't he?
As far as this ⬇️ concerned:
He also said “if I do anything stupid to myself if you leave then please always remember it wasn’t your fault”.
I'd agree. It definitely would not be your fault - it would be his decision. If he says this again when you've separated, you can always ask the police do do a welfare check on him but I suspect he's saying this to manipulate you.
Anyway, why would you be the one to leave?
Whatever, his current actions are not good for your mental health, do ensure you get professional counselling, just for you, if you need support. And, of course, reach out to good friends and family for real life support. Good luck to you OP. 🌹