My fiance was also treated through the VA. We looked into the situation back in 2003-2004.
The US military / government has determined that HCV will not be covered as service-related.
Approximately, 80% of those with HepC are military veterans. If the government were to determine that HCV infection was service-related (and they did briefly), the expense would be astronomical. My personal opinion is that the ruling will not be changed, for that reason.
However, as a veteran, you are entitled to medical care at any VA facility. There are a number of websites by veterans, for veterans providing information about dealing with the red-tape and getting treatment.
Fiance had HCV, cirrhosis, ESLD, ascites, and portal hypertension. Was transplanted June 2004. Now, on interferon and ribavirin. Hepatitis C is back.
If God brings you to it, He will bring you through it.