Gail,
You are certainly not alone in how you are feeling and processing your emotions right now. I implore you not to act on those feelings of loss, however, as the reality is quite different. You are a mom of 5 children. Would you really want to spend the rest of your life with a man who did not love and want to be around your children and eventually grandchildren? I personally cannot think of anything worse. My children are my life and even though they are more or less on their own now, I still so enjoy having them around, travelling with them, experiencing new things with them. I would want my significant other to enjoy those things too and not be looking for ways to avoid them. Imagine how they would eventually pull further and further away from you as a result. I personally will not date someone unless they have children and have a very good relationship with them. This is to me the best test of what kind of man he is and how he has lived up to his responsibilities for his family despite the breakdown of his marriage.
If your n xbf is into the personal sites, he is probably also into pornography and other less desirable, but very n characteristics. Especially with the distance between you, he could carry on whatever kind of lifestyle he chose and you would be none the wiser. My xh did it right under my nose and I didn't figure it out because I trusted him implicitly.
You have gotten lots of good advice here. I hope you can take it to heart and do what is best for you and your children. Hang in there darlin', we're pulling for you.
Hugs,
Brigid