I took out student loans to help me goto college while I was involved in drugs and alcohol.?

I took out student loans to help me goto college while I was involved in drugs and alcohol. I ended up quitting school and spiraling downward. Needless to say I was very careless and my loans went into default. I ended up trying to kill myself in 2009 and going into rehab. I ended up getting out and my life changed dramatically. I started taking care of myself and caring about what I do with my future. I ended up starting a non-profit to outreach to teens who are going through the same things I faced and eventually overcame, so they don't have to go through what I and many others have. I take full responsibility for what I've done and I want to do what is right, but I run this nonprofit full time and I don't make the money to pay my balance in full. I offered to pay a minimum balance and Sallie Mae just wasn't having it. The guy practically made fun of me because I said I live by faith. I'm not saying that I shouldn't pay this back, because I know I should, but while running a non-profit full time, I don't have much time to get another job to attempt to pay this back. Does anyone know what my options could be? I mean, I made mistakes and now I'm facing a huge repercussion for it. I just want to be able to move on with my future, but this lingers around like a ghost of my past and I just don't know what to do. Any ideas?