You are absolutely not a fool.
He has chosen to be far less than honest with you about money (and possibly a lot more -- who are his friends, what happened with him and his family, etc) and has revealed himself to be nothing short of heartless when you needed support from him: all of that speaks volumes about him, not about you.
On top of everything else, when you are naturally devastated at all this, he has trotted out the line of the truly self absorbed, the old chestnut -- 'you are overreacting'.
I think you are dealing with a very troubled individual here the delusions of grandeur and the spending to the point of (and in the face of) massive debt, the people from his past that he is no longer in contact with (his parents and possibly more that you haven't heard about), the way he has split his life into several sections the 'relationship' with you, the 'friends' he has been involved with in business -- and the fact that he thinks there are parts of it that are none of your business. This is all very, very bad.
It is no reflection on you as a strong and whole woman that you would be completely unable to change this man. Please accept that you would never put a dent in his way of looking at life and his way of looking at other people and do not stick around to try, or feel that he will be your project, your challenge. Focus on your own life, on your own family, on your own future, your own financial security -- without him.
Nobody means enough to this man to change. Everyone else will always be wrong and he will always be right. Nobody else's life will ever be important enough to make him stop and think about what he is doing. You have seen some of that already in his comments about your problems vs. his far more important problems. You have seen some of that in the way he continues to spend money he does not have (this is called stealing) without apparently an iota of remorse or worry.