This is the last resort. The nuclear option, so to speak. Hopefully, you won't have to take out private loans…but many people do.

Thankfully, not every lender tries to suck the very marrow from your bones. Pay close attention to the terms of your repayment, as lenders sometimes jack up the interest rate once the grace period ends (source). 

And whatever you do, try to limit your reliance on these bad boys as much as possible. Or get comfortable with thrifty living…forever.