Yours is a very normal response and one that I don't think anyone thinks of. I remember when our first child went away to college. The summer before she left was so exciting for both of us. We shopped for linens, clothes and everything that would make her dorm room just perfect. It was like we were planning for a trip. I just never quite understood that it didn't include "me". We drove to her college and got her all settled and I'll never forget driving out of the parking lot with her waving from a second story window. It all hit me like a ton of bricks..... She was now going to college and "I" wasn't part of it at all. I cried all the way home. (about 4 hours) I said at the time that they needed a support group for moms who send kids to college. The kids get all of the attention and recognition after we have spent the last 18 years of our lives worrying about them, caring about them and having them in our lives 24/7. The pain does go away eventually but understand that you are not alone. I sent her little "care" packages with goodies and such---that helped some. But, talking to other moms going through the experience helped the most. It's a good time to start that new quilt, too.
HUGS--Joan--been there, done that 3 times