GranJan60, I can totally understand how you must be feeling right now, but it will get easier. Just because they've moved away, it doesn't mean you'll never see them again ... it's only 2 hours away, and that really isn't very far when you consider that there are so many grandparents whose grandchildren have moved overseas.
Give yourself a little time to get used to the idea, and then start to think about things that you'd like to do to fill your spare time. I don't know whether you have a partner, or whether you're alone, but there's plenty of things out there to enjoy either way.
Perhaps, once they have settled into their new home you could visit occasionally, and stay for a night or two if they have room, or book into a local B&B/hotel, and enjoy some time with them.
One thing I've learned, since my children/grandchildren moved away from home, is that we can't live our lives around them forever. I did used to wonder what I'd do with my time if I wasn't working, or looking after children, but now I find that I have plenty to do, and don't have time to worry about not seeing them so regularly. Of course, I miss them, but it's nice to have some 'me time' now, and to be able to do things that I enjoy doing.