Sorry you're feeling so depressed Debbie. We have the exact opposite problem. My husband is being transferred to FL, Orlando area specifically, and my daughter is in college in Philadelphia and will be entering her junior year. She is sooooo angry with me right now for moving. She feels I am abandoning her and the rest of the family for as she puts in "palm trees and a few more sunny days". She doesn't understand how I can leave potential future grandchildren, asks me "don't I want to be close to my grandchildren", etc. Mind you, she will be 21 in December, has no idea where she will be working after college, and has a boyfriend in a band whom she is very serious with.
I told her "proximity" does not equal "closeness". I pointed out that she has two grandmothers within ten minutes of driving distance and she is close to neither, and neither grandmother made a point of being involved in her life. I tried to get her to understand that I can't just sit here waiting for her to see where her future takes her. I told her I would love for her to come live with me in Florida, and she can visit as often as she wants, that I'd pay for her airfare, and if she needed me for anything I would be on the next flight. We were VERY close up until about 4 years ago when she felt my rules were too restrictive, she was turning 17, and her father, my ex, promised her a new car, etc., so she moved out while I was away and moved in with him. He only lives around the corner from me, but I still felt it was not the right place for her to be as he was never home, and there were no rules imposed. Fortunately, she has a good amount of common sense and didn't get into any major predicaments. I told her that if she was a part of our household and wasn't able to come with us then we would most likely have had to pass up this once in a lifetime opportunity, as we would never make her leave her home, but she has made it clear numerous times that "home" is with her father, who by the way, didn't do one thing for these kids while they were growing up except bring home a paycheck.
Sorry for going off on a tangent, but I think it is wonderful that your daughter feels secure enough to do what she is doing. I know you will miss her terribly, as I will also miss my daughter terribly. Just call as often as possible, email, IM, visit as much as you can, keep the lines of communication open, ask about her life, her troubles, her joys. You can do this!! Plus, you get to go to Florida more often!