You are leaving a lot out here OP.
What is your household monthly income about?
How much do you have left over from the rented properties? Could you take over the management for them?
Are you mortgage free?
What is his salary?
Things have shifted now you aren't primarily a mum in your role.
Does he want you to have money to enjoy your free time?
Why don't you put the expenses on the credit card? Keep your allowance just for you?
How much is he suggesting he reduces your allowance?
Why not suggest going cards in joint accounts?
You need to sit down and have a long chat with him about where the household finances are, a plan going forward.
Do you want to work?
How long does he intend to work for?
£1k plus a credit card is ok on the surface, you don't say how much the reduction is.
Money is just money you should be able to talk about it openly.
If you do need more to retain your lifestyle and he thinks you are in a position to work, maybe part time, but you have no intention of working, then this needs to be talked about.
Flinging about words like "I'd get half if we divorced" isn't very helpful if you want to stay together.
If he has earned all the money throughout the past 2 decades or so, not been financially abusive which it sounds like he hasn't, his input and how he feels should be respected.