Your sister leaving will be a challenge for about a week or two, but you will get rapidly get over it. With today's technology, you can not merely talk to her on the phone, but see her
while talking. Cool! There are some advantages; you now have a new place to go, you will get first hand knowledge of what to do & not to do in college, you can mooch in to meet some of her new friends, your parents will baby you and give you more stuff. Heck, maybe I can move in and be there & your parents can take care of me when YOU are gone!
It will not be all BAD, I'm just saying!!