I think that you are unwilling to look objectively at your husband's behavior because he has systematically disempowered you. Even if you got incontrovertible proof that he is gaslighting you, there's little you could do about it because he has all the financial power and you have none.
You need to re-empower yourself.
I think that you are smart to work on getting your drivers license. The issue will be saving up for the lessons given your low income and the setup in your marriage where you only have access to your own earrnings. Stop contributing to the other bills, clothes, food, etc. Maybe you can tell him you don't have enough money to contribute. You may or may not want to disclose that this is because you are saving for driving lessons. He may say that you don't need to drive because he can do all the driving. Don't fall for this - it's just another way to keep you under control. Fall back on some other explanation: I'm worried I can't get the kids to the doctor if one falls sick, I need to learn to drive. Something like that.
Learn how to surf the internet without leaving a history of websites you have visited. This will help you start learning adult financial skills and getting an understanding of what your husband is doing.
Get onto websites and find the deed to the house. Whose name is it in. How much is the mortgage. What bank holds the mortgage. How much is the payment. etc.
Start learning about mortgages and the other financial issues you don't know about. Pensions. etc. Is he saving for a pension for you? Are you entitled to his pension? Or not? What if you divorce? What if he divorces you? And can you be "disinherited" from his pension if he signs certain forms. You need to know these things.
You need to know how much money he is keeping from you. How much is he saving while you can't even afford to get driving lessons.
Do all these things without leaving a history on your computer.
Do what is required to ensure you do not become pregnant again. You are not in a good situation and another child to care for would make your own situation even more unstable.
You do not have any help with the children because he is never home on the weekends. You have zero time off. Meanwhile, he has two full days off during the week with no childcare responsibliities. And he wants you to have a fourrth child even though he has no plans to start taking weekends off. This in itself is problematic treatment of you. So you do need to empower yourself.