When my oldest daughter started to apply to only east coast schools I started to panic a bit. I had never thought that one of my kids would want to move so far away. I had to keep reminding myself that this was her life and she needed to make the choices that were right for her. But I had several angel/devil moments. I would say “being so far away will make it hard for you to come home and we will miss your birthday this year for the first time”. But then I would mentally kick myself and say something like “you have always been confident and strong and I know you will succeed wherever you decide to go”.
The thing to remember as your child goes off to college is that it is all about them. Even when they are 100% sure they are going to the right school they are going to feel anxiety about leaving their family and friends. They are going to be living in a small room that they share with a perfect stranger and may share a bathroom with 30 other people. Wearing flip flops in the shower is really no fun. The food will be foreign to them and they will have to do their own laundry sometimes in another building. It is a huge change for them and they need to know that their parents support them and believe they have the skills to succeed on their own. They will not only worry about themselves but they will worry about you too.
Save your tears for your trip home. It will be hard when you say good bye but try your best to think about what they need from you. They need to know you will miss them but they also want to be sure you are going to be OK and that you have confidence in them.