My youngest, 26, left for Canada last week for two years but is going to try for residency. Although he has been away a lot before I feel this is the big move and like you I felt so sad as happy as I am for him. He has been a great support to me these last two years and I love his company.
However when I saw his room I cannot wait to get in there and clean clear it up and I love the fact the rest of the house isn't covered in his stuff!
So now I'm enjoying it just us two and dog. He sends me loads of pics of him driving across the rockies and I know how happy he is so all good, and I've already got used to daughter living in oz, and other son and two grandchildren live near by so my nest might be empty but it's quite fun sweeping out the eggshells!