Have you called who ever is taking your account to collections and tried to negotiate more time or a payment plan?

Explain that sending it to collections is bad for you and them. If you don't have the money, then you don't have the money. But if also have to deal with a collection agency then you'll have more stress to deal with. Also the collection agency gets a cut of your (current non-existent) money owed.

If you can explain that is in both parties interest to keep it out of collections and extend the deadline or work out a payment plan, you may be more likely to get out of this situation without damaging effects on your credit.