Snowflower, he has created a no win situation for the both of you.
Sweetheart, you need to give yourself a good shake!
Imagine a woman coming on here and saying her husband had previously been unfaithful, been forgiven and was now refusing to let her see his phone. You know that everyone would say he needed an ultimatum.
You are in the same boat. He was secretive about your JOINT income (ie you both contribute to his ability to earn that money, according to the law), and he is being secretive after previous issues where he racked up huge debts.
It sounds as though last time you found out, he was economical with the truth and you allowed him to be.
Many people couldnt live with a man like this, because his assumption is that his salary is his alone, and that can only mean that he sees you as a junior partner in the marriage I certainly couldnt, and believe me, I have put up with some crap. It is not the 1950s.
IN your shoes, I would not ask for, but DEMAND, full transparency, or leave him and save my half of the assets, if it is even possible. Because as his wife you are jointly liable for half his debts anyway, are you, in the sense that if you sell, any debts have first call on the asset, whoever incurred them. Someone else may be able to confirm this.
Of course, just like the unfaithful husband, there is only one reason for his secrecy- something to hide.