You did just fine. W is mad and pushed your buttons on purpose because she does not want to look inward at the real problem and that is her. If she really does want to be custodial parent then she needs to step up. She needs to take care of the girls as much as you. I know with my H gone, I knew that I wanted to be the custodial parent so I have done everything possible to show I can handle it. I have made a support group of people I can call in case I can't take off of work, need a break, or something else like going to therapy, which is good and showing I am getting help. Your W has done nothing! She needs to step-up or you should fight for custody. That would be hard on the girls, but they would be better with a parent that puts them first and not a career.
Keep standing your ground! Unless it is your time to be with the girls, W should stay home and be a mother. She will start realizing what she is missing or what a divorce would do when you actually make her see the realization. Make sure the girls are taken care of, but she needs to be inconvenienced as well.
Stay strong.
Me29 S3 H left 4/1/09 I file 8/2/10 Divorce final 5/17/11 1st http://www.tinyurl.com/25lhu52 2nd http://www.tinyurl.com/2c35ueg 3rd http://www.tinyurl.com/322yk89