You cannot get hepatitis C from herpes because it is a different virus. However, hepatitis C can be sexually transmitted and it is possible that you may have been exposed to hepatitis C at the same time you were exposed to herpes. I comment on the role of liver biopsy quite a bit in my patients with hepatitis C and as a general rule, we often recommend it. In most individuals with hepatitis C it is difficult to tell how much damage there is to the liver without a liver biopsy. In your case, if your liver biopsy is fairly benign with little fibrosis, your hepatitis C is unlikely to be a cause of either your itching or impotence.
Liver disease can cause both itching and impotence but it usually has to be pretty advanced.
If your biopsy does show significant scarring, you might want to consider therapy. I am very sympathetic to your concerns about protecting your wife and three children. You really are at no risk to your children. You should not share razor blades or toothbrushes and you should clean up any of your blood with alcohol. The situation with your wife is a little more complex.