You have no reason to feel guity...... From what you write, she walked away...... On top of that, she seems to be a very screwed up woman..........
I would personally go off with the new woman.... and have a great life........ Leave the screwed up exW to the other two clowns.....
Just my 25 cents....
Take Care,
NMD
"Chains do not hold a marriage together. It is threads, hundreds of tiny threads which sew people together through the years. That is what makes a marriage last --more than passion or even sex!" - Simone Signoret