I want to comment on this one thing that your wife said and offer some advice, which of course you do not have to take, but it is offered with the best intentions:

"they will be ok after we separate"

You and your children deserve better than this. Tell that selfish woman you've been patient and supportive of her and her needs long enough and it is past time that those little children are put FIRST.

It would be in the best interests of small children to have parents together, but if that isn't possible they should live near each other. Small children want and need to see both of their parents often. Tell this woman you expect her to remain an active part of their lives. Give serious thought to where and with whom the children should live. Mommy might not be the right choice as the residential parent.

I think this is so important that I would purposefully drag my feet on a divorce, just to force her to go to counseling with me to make healthy arrangements for the children--and I'd have no problem telling her that, either. I believe you would benefit from individual counseling too, to help you develop healthy boundaries and personal expectations and how to meet them. By the way, whatever she has done for herself, you could do for yourself: get more education, get a better job, etc.