Welcome to the forum. Turn the clock back a year and I was posting on here as youngest was off to uni. There was a huge response.

From reading your post, you obviously have a great relationship with your daughter and is there any reason why that should change??? Absolutely not. You can enjoy each other's company in just the same way and you will come to appreciate your home life with OH that much more.
It will feel better each day. Don't forget you have also gained a son!!
G