And, unfortunately, college is not a right. They do not have to pay for it. So, you need to let that piece go and find a way to finance that debt to give you time to pay.
I agree - you should sit them both down and explain that they have hurt you and they need to stop. But, make sure they know that you will not allow them to continue the pattern with your brothers.
Kids - divorced or not - have no place in finances of their parents. But, they do need to understand limitations that the parents might have financially.