Staying in a marriage for the sake of the children is not a good reason to stay, the children will know that their Mom is unhappy. Trust me on that one. You need to decide if you want to repair the marriage, communication is key, are you interested in couples counseling? That will work if you both want it too. But it sounds like this is not what you want? Separation and divorce can be stressful but ultimately may be best for all concerned and it can be done so your children are happier too. Lots of decisions to be made, I wish you luck.