Peace be with you xboxisdead; and I hope you can find peace;
I am sorry, but I disagree with just about everything you have said.
Whereas the other, the house is empty for new nest. New wife. Maybe better than the old? Maybe more beautiful than the old? Maybe kinder than the old? But what about the children??! - boohoo boohoo boohooo - I will reply to that, "What about them?". Ever thought perhaps that the new children also may be better than the old? Ever crossed your mind. You can make more children anyways.
You can't treat a wife like a pair of shoes, a wife should be for life, until death do you part. Having been married 39 years, full of arguments and disagreements, there were so many times I could have walked away, but I didn't. There were times she wanted to leave, but she didn't. When things go wrong, you fix them, rather than walk away. Your wife is more important than your children, you marry your wife not your children. Get things right with your wife first, then it will be far more beneficial to the children.
Put the children first, and the chances are you will mess things up first with your wife, then with the children.
Think of children as .... say pets...or cats. You lost a cat; you get a new one. Same with children.
You are talking more about a sperm doner. A husband and father is a far more demanding role, and takes a huge amount of commitment. Marriage is probably one of toughest things we do in life, nothing prepares us for the turmoil ahead. Rather than expect to be with the best possible wife, strive instead to be the best possible husband. Fight all battles with kindness. Pray that Allah will bless your family, pray for guidance.
May Allah bless you on your journey,
Eric