You should ask your doctor your question. That you had seen elsewhere fasting was needed for the test and what, if any effect on the test result would having eaten prior have.
I did find this on the NIH web site
“Although FibroTest may be performed on blood samples from fasting or non-fasting patients, FibroMAX must be performed on samples from fasting patients.“
So it looks like it depends on the specific test used.
But I assume that if you did take a test that does require fasting prior that you will need to repeat the test as the results may not be valid. But you should discuss your concerns with the doctor (or the nurse) who ordered the test.
Why were you having the Fibrosure test? Have you had hep c for many years?
I have read that in general for patients infected with hep c only about 20% will develop advanced liver disease after 20 years of infection.
I know for me I was infected for 30 years before I was diagnosed with cirrhosis in 2008.
Best of luck to you