How to avoid divorce for children's sake under the situation we have separated for more than a year

Since last year, I've had trouble divorce with my husband . Though we have two children and own house, he left home a year ago and I heard that he has seen someone since 2012 before he mentioned divorce. And their relationship has been continuing.One year+ has passed since we separated and I started part-time job. I've taken care of children.i want to avoid divorce for children's sake. And house's mortgage(his and my name as title on the contract )has been left and he has paid all of monthly mortgage.Under the situation, I said to him that until children become 18 years old, he should continue to pay monthly mortgage, $2300 per a month and then I would agree with divorce. It must be hard for him. That's why I said and wished that he must have rethought and get back to us.but Now he agrees with paying mortgage and asked me to discuss divorce settlement. To avoid divorce, I told him that I have been busy for children and had no time to do. I tried to ignore it.I need your good advice.