Why can't I face the music???

I have been unhappily married for a really long time. In fact, we went through marriage counseling about 3 years ago. It did not really seem to work at the time. My husband is now really cooperating and I feel it is just too little too late. We have two children. I am really scared to divorce as I don't want to raise the children without a father. I am also afraid of being alone. My unhappiness is affecting our children now because I am almost always aggravated, teary eyed and guilt ridden because of the way I feel. Anybody elso out there in this situation now, or ever been there, done that??? I really think I need to make some BIG decisions now with a new year on the brink. Please, serious answers only.