"I'm about to tell my wife that I want a divorce.  I'm really nervous to break the news.  I know she's going to be upset -- she doesn't want the divorce. I'm also afraid I'm going to lose everything, from the house to the children.  How do I handle breaking the news to her?"

Timing is important. Don't break the news when you are about to go to sleep. Consider a time when you and your wife will be alone together, without the children present, and when neither of you is tired or angry. Be direct, but be kind. Rehearse what you are going to say. Think about how you would feel if you were hearing this from her. Use “I” statements, not the accusatory “you” statements. Don’t give out too much information at one time, as while you may have been planning this for a long time, your wife may be shocked and confused by the reality of divorce. Give her reasonable time to absorb this. Your tone and approach will do much to reassure her that you want to resolve your divorce amicably.