Congratulations on your considerable achievements. From what you say, you are making some very mature and reasonable decisions about the direction you want to take. You’re probably right that your parents are frightened for you. The economy stinks. You have what seems to be a sure thing in the acceptance. They saw smooth sailing ahead for you and now you’re making waves.
But here’s the thing: At some point, every young adult has to separate in order to become a full adult. Sadly, that separation often seems to have to be done in anger. It doesn’t. You are not separating from loving your parents. You have no desire to drive a wedge that will be permanent. What you do want to do is to claim your own path. Since you are paying for your own graduate education, you do have the right and the responsibility to choose for yourself.
You can’t fix the conflict. But you can fix the anger. Stop arguing. Arguing gives the impression that you can be talked or argued out of a decision. Instead, emphasize that you love them very much and wish they’d give you their blessing. But be clear that your decision about what you study and the career you choose is yours to make. If your folks invite you to fight about it, simply restate that you love them and that you know they want the best for you but that you are clear about what you are going to do. Then change the subject to something you all enjoy. Be sure to express your appreciation to them for raising you to be the kind of person who has had the courage to travel abroad, the dedication to do so well academically, and the appreciation for the importance of family. They’ve raised you well but now it’s time for you to take on responsibility for yourself.
I wish you well.