Oh boy, that was a huge overreaction! The way online banking works nowadays, it isn't so easy to just take all his money and run into the sunset. For example for my bank I need about 3 codes just to get into my bank account, and then for online transfers (which I assume is what he is afraid of), you need to insert your card into a pocket calculator type of device and extract another code and confirm the transaction and then the bank sends you an automatic text and the cycle continues. Some other banks have limits on how much money you can take out weekly and unless you go to the bank in person they will flag out all the large transfers. And when I'm saying large I mean just a couple of hundred bucks or so. He is being ridiculous.

Now, the problem is not his bank account, is the way he was screaming at you and treating you like a child who needs to be disciplined. Is he abusive in any other ways? Are you willing to spend the rest of your days with someone who treats you like this every time you to have a misunderstanding?