When your federal educational loans are in default, you have several options:
You can repay the loan in full.
You can negotiate a new payment plan with your lender.
You can "rehabilitate" your loan.
You can consolidate your loan.
Obviously option one is rarely attractive or possible for defaulted borrowers.
Option two (renegotiate) should be investigated fully - most borrowers skip this step, but it's probably the best option for most people. Call your lender and ask to speak to someone in the "Workout" Department. Explain your situation to them (there's nothing unusual about it) and ask what options are available to you for switching to a graduated, extended or income-sensitive repayment plan. If your lender will agree to change your repayment plan, a few regular payments will get your default status removed, and the new plan may be easier for you to keep up with.
Option three (rehabilitation) is really a specific form of a workout agreement. It probably won't help you much in your situation, because it requires an agreement between you and the lender that will allow you to make 9 consecutive on-time payments of some agreed-upon amount.
Option four is everyone's favorite, but you must absolutely understand what a consolidation loan will do. To keep this utterly simple - a consolidation loan is a brand new loan that will pay off your old, defaulted loan. A consolidation loan MAY lower your monthly payments, but understand how this works. A consolidation loan never lowers your payments by wiping away some of your debt - a consolidation loan lowers your payments by stretching out the length of your loan. If you pay less every month, you'll make many additional monthly payments, and - in the end - you'll pay far more back than you would have paid on the original loan.
As an example: Suppose I lent you $100 and you agreed to pay me back in 2 weeks by paying me $50 a week. You came back a few days later and explained that you weren't going to be able to afford to pay me $50 - is there something else we could do? "Oh, absolutely," I'd say, gallantly. "Instead of paying me $50 a week for 2 weeks, how about if you only pay me $10 a week for 17 weeks?"
See - in the end, you'll pay me back $170 instead of $100 - that's how a consolidation loan works. But remember - we're not talking a $100 loan for a couple of weeks - by the time you pay that $5000 loan of yours back over many years, you'll pay a few thousand more than you might have paid if you didn't consolidate that loan.