With partners in long term committed relationships, it is preferable to be frank and open. Though the risk of HCV through sexual relationship is low, (almost nil in case of monogamous long term heterosexual relationship), other issues such as trust are equally important. Do get to know the other person better before you disclose your HCV status.
Health care professionals are prohibited from disclosing your HCV status without your approval by Health Insurance Portability and Accountability Act. Inform the insurance company if insurance is paying for your treatment.
Disclosures on social media are neither warranted nor advisable. Join a support group, but exercise caution about what you share on public forums if you value your privacy.