Hi Christmas
As has been said you will have to come to a new arrangement over the finances. It's a concern that he always has a lot of money in his wallet and he doesn't notice it goes missing, that doesn't bode well for the future as his capacity declines.
You need to do some financial separation particularly as if the bank get wind of it they sometimes freeze an account and there's no mention of you having an LPA so you need to get money in your own name which you can access if needed.
If your husband can't keep track of what's in his wallet then can he keep track of what's in the bank account, it not then it would be easy enough to open a second account in your name only and start moving money into it.
My wife used to do all the money side of things I just had a cashcard on the joint account and took money when I needed it, but over time I've had to change all the bills over to my name and learn all the bits about keeping the car and house insured, council tax paid something I'd never had to bother with in over 30 years, she'd always managed the money and that suited us.
It is an issue you'll have to address and I guess handing over control of the finances is a big one like stopping driving, giving up work and learning you need to accept help, it's all very disempowering having these things take from you and relinquishing control to others, it can be very damaging to the self esteem for men and women.
Perhaps the most helpful advise would be how to start this conversation with him would be the most useful advise, it's something better managed than waiting for a crisis.
K