Student loan repayment plans

I am 26 years old and recently graduated from grad school. I have about $28,000 of loan debt, from both undergrad and grad school. My deferment is up next month, and without changing or consolidating anything, I will owe more than $500/month. I work for a non-profit and cannot make that high of a payment. I know I have some options for repayment and consolidation. I am trying to find a balance in which I am paying what I can afford each month, but not extending my loans so much that I am paying an absurd amount of interest. Elisa, Bozeman, MT