I have been through this a few years ago, P60, and the hurt was very deep. It left a massive hole initially, but with all the technology around, its honestly not as bad as you imagine. You will settle into a pattern with your family, and that may mean its Skype with Australia, and that will be so much comfort to you. We skype every month or so, see the grandchildren, catch up on what they are up to. We also have a Whatsapp group just for us family, and that is great cos we tell each other work news and other stuff.
Yes you never think you will accept it, but you do, and it becomes the norm. And then you start to feel happy for them, and proud of them, and glad that they have such wonderful lives and opportunities they wouldn't have here. We are so lucky this year, as they are all coming over at xmas, we have helped them out with the fare, but it will be wonderful to show the grandchildren a proper English christmas time. We never thought this would happen, so we are beyond happy. It will be heartfelt when they leave, but we know it will settle back down to be what it is.
Take heart P60, you will not always feel so bereft, your emotions will be shuffling for a time, but it will settle. Sending you kind regards, and hugs