I really really think you need to see a therapist to help you unpick this.
You seem to be stuck, you know it’s wrong, but you are looking for the ultimate ‘why does he behave this way’. If you could find this elusive answer would it make a difference to whether you leave him or not? If someone posted - oh yes men get to a certain age, see death around the corner and start obsessing about money- would that make you think it’s ok and it’s ok to stay? Maybe you are just looking for a reason to stay (sunk costs), but your head is telling you to leave.
Or do you think if you know the reason why, you can come up with the argument that will stop all his nonsense. For us other posters, looking in and who have been through similar it’s obvious, he doesn’t have your best interests to heart.
It may be that when he divorced he felt cheated that his ex wife got a share of ‘his’ money. She may have married again and had a dozen more children, so he sees the wealth their children would have had, has diminished. Whatever the reason, he thinks his feelings count for more than yours.
You could try saying, yes if we’d had a child I would have wanted to combine assets, but we didn’t, so I don’t.
The ultimate test of having a controlling partner is the feeling that ‘if I could just find the right words, they would understand”. But they understand alright, they just want to get heir own way.
My STBXH is a controlling bully. It took therapy to understand this. Save your Xmas money and pay for a chartered clinical psychologist.