Does your family object to your relationship because they think they can convince you to leave?
It's important to consider this carefully, because you're in a hormone-flooded state right now. You have cultural differences and age differences that will present problems in the future. The problems can be surmounted, however, if you are both able to be mature about it and work through the issues. I don't know if you've met his family, but it's a good idea to do so as soon as possible. By all means, let your family know you're still dating this man.
It's time to grow up and let your family know that you love them, but they're not in charge of you. Whether this relationship succeeds or not, your family should know that it's what you're doing. They don't have to know details. You can let them know each new stage as it happens -- don't project too far into the future. "Mirrors and Teachers" and "Creating Family Acceptance" have helpful information about responding to your family in a different way.