Of course there are no guarantees in life. You may indeed spend all this energy and have her walk in the end. But if your efforts delay her by a month or a week, that is more time for your children to have had a whole family.
You say you love your wife, describe the heartache you will feel if she leaves....Please tell me what else you would rather spend your energy on?
At the same time, you do need to remember to take care of yourself. You don't want to run yourself down, physically or emotionally, trying to be Superdad or Superhusband. Do what you can, what feels right, what may make the biggest impact, and take a break when you need to. Leave the rest. Leave the dishes in the sink once in a while--it may remind her that she never has to clean them.
