P.G.
You need a social life, but speaking from experience as the kid of a dating mom who was on the selfish side, you need to decide what you want to do. Do you want to have adult friends and enjoy adult time, or are you looking for a longterm relationship/potential spouse? If the first, just keep the dating life separate. The kids don't need to be involved with your adult friends. If the 2nd, remember that everyone you become seriously involved with must realize that they are involved with you AND your children. You're not just you, you're a family unit, and whoever you date needs to understand that. OH, and don't introduce the SO until you're engaged, and make it a long engagement. It's torture as a child to let down your guard, get close to someone who "might" become family, and then have them disappear - over, and over again.
Your kids are yours forever; be careful with their emotions. Take care of yourself as well and enjoy your life. :)