As eluded to above, once you get started there - in orientation or classes, all this anxiety will fly out the window. You are in the limbo period between decision made and getting to that decision. The same thing will happen when you put an offer on a house then have that time to wait for it to close and get your keys. There are so many other grown up decisions you will make going forward that will leave you feeling edgy and uncertain. It is normal to wonder, “What have I done???!!!” for the major things we have to decide on in life.
Big decisions and changes take time to adjust to. You will love it at Dartmouth. Don’t ever apologize for going there to anyone or yourself. Own it proud.