My federal loans are running out, I have 2y of medical school left & don't have co-signer 4 private loans.

I am already $130,000 in debt. I am still in medical school and federal student loans are running out, I don't have any one that can co-sign for a private loan and anyway, I am sure getting more in debt is not the way to go. I am 29 y/o and am full time student. I am worrying about my future constantly. I would like to invest but I don't have enough money to do so. And in the years I am in my only option of a job would be to start my own business but even that takes the time and money I don't have. What can I do? What should I do? I need an income to finish studying or I won't be able to do so. Can anyone advice me on what to do please?