Now that I am married, How can I get my parents back off!?

Don't feel that you still have to answer to your parents and don't give excuses. So many people say no and then start explaining why and trying to justify their reasons. Your reasons are yours and they are valid. Don't worry about it. RSVP to the family and let them know you won't be making it and you'll see them at the wedding. When your dad asks if you are going, say no and nothing else. If he asks why tell him you have valid reasons and leave it at that. Maybe he'll get the hint.