Debt sent to collections

I was denied a financial aid appeal (3rd one, due to health concerns at the time)
I finished the semester and owed $4000.00
I was unable to pay, and now it has been sent to collections.

What do I do now?
I would like to return to school to obtain my BA, but do I have to pay that old debt first?

I could ask someone to co-sign a private student loan, but would it cover the old debt and a new semester?
Can I even get a private loan with financial aid hold?

You will not be able to register as long as you owe the school money. You are in a catch 22; you will not be able to get a student loan unless you are enrolled in classes. You will not be able to enroll in classes until you pay the money

Get a job…pay off your debt. Then return to college.

And when you return, pick an affordable place to attend school to finish that bachelors.

Has it been turned over to a private collection agency or just the collections department of the school?

Either way you need to get a payment plan set up. Don’t ignore your collections mail/communications. Keep a record of everything and your payments including screen shots of online balances. Private collection agents are notorious for not processing payments in a timely manner so they can assess late fees and penalties. Your debt can easily grow to an unmanageable amount by ignoring it. If you need help understanding the fine print or have a question about your rights you can contact a Financial Aid officer at your school (even if the debt has been moved to a private agency) and they can provide you information about your rights as a debtor and help you understand your options for getting this resolved.