I am a student pilot working on my commercial license, during a recent solo flight I had an over speed in an r22 which resulted in the engine and rotor RPM going up to 115.% I had my head down switching the radio frequencies and when I looked up there was a huge bird heading right at me, my instinct was to push down on the collective but in the process of the panic while doing that I over powered the governor and increased the throttle on the descent. engine rpm and rotor rpm quickly rose and I pulled on the collective get them down but it was too late. They had already gone above their limits. I turned around and returned to the airport and reported it when I got on the ground. The helicopter was grounded and maintenance inspected it today, they said there was damage done to it and now the flight school and holding me liable for the cost of repairs, the student agreement says that the student is liable for repairs up to $15,000 in the r22. I was lucky enough that I did not hit the bird otherwise It would have definitely destroyed the helicopter. my question is, even though I saved my ass and the helicopter even though It was damaged in the process the school told me I am liable for the repairs $7500-$17000 it is a lot of money and I'm just a vet you see my GI Bill, I don't have that amount of money. Any thoughts? I don't have renters insurance either.