I'm not completely sure but I do not believe any of the common income-driven plans take into account your expenses. Instead it's based upon a percentage of what they determine is your discretionary income based on the income information you submitted. For example the income-based plan is 15% of your discretionary income and the REPAY is 10-15% depending on when you first borrowed. If you use REPAY and you're married you have to use both incomes though. You can use the calculator on the student aid gov website to give you a rough estimate of what you would pay. https://studentaid.ed.gov/sa/repay-loans/understand/plans/income-driven I've found the payments to be very low. As a last resort you could still try for a hardship deferment, although that might put your loan forgiveness on hold.
If you're having trouble with the private loans you might contact the lender and see if they have any options. This is not an uncommon thing with the astronomical cost of high education. Good luck!
