Marriage is a contract. Love is an emotion. Men need women for different reasons and love them for other reasons. Oftentimes love goes thru cycles; you love her, don't, can't stand her, and love her again.
Our ***** in bed, then mother of our children, then companion and partner, then nurse.
You can learn to love her all over again or bail out and find someone new. You should wait to see if the cycle swings again though. Try to make some of the old spark rekindle the love first.
You already know that it's over.
You have to make a terrible choice.
1) Keep everything the way it is until your kids are grown
2) File for divorce and fight for custody of the kids. In most cases, the father gets screwed over, in this respect. If you choose to go this route, DO NOT MOVE OUT until the divorce is final. Otherwise, the courts will rule that you have abandoned your family.