My Son Was Diagnosed With Keratoconus 2 Days Ago. His

My son was diagnosed with keratoconus 2 days ago. His sight in his left eye is severely deteriorated and it was determined that he needs cross linking surgery in his right eye to slow the progress of kerataconus in his that eye. My wife and I'm are terrified and concerned about this and want to do everything we can to help him. The Eye Institute has said the cross linking surgery will cost 5000 dollars and may not be accepted by our current insurance GEHA Aetna. What can we do?