You have a few options to get a masters without going into debt. The government offers grants; you will need to fill out a FAFSA at http://www.fafsa.ed.gov/ to see how much funding you may be eligible for.
Also consider that many masters programs let you enter part-time. This is helpful because you can work while getting your masters. In that case, you may even be able to find a job that will help pay for your masters, if your job is related to the degree you are getting.
Also, keep in mind that most student loans are considered "good debt," meaning you will have a low interest rate and credit agencies will see this as good debt in relation to your credit score.