his logic is always so sound I do feel at fault. I
That right there is problem number ONE.
His logic is fucking bullshit. Around here we call it "rugsweeping". To my knowledge you did not force him to go out, for the last 6+ years, and have sex with other women.
It is not your fault he cheated. it's HIS fault and until he is ready to accept that, there isn't a darn thing you can do to repari the relationship, if that's what you want.
Please go to the Healing Library in the upper left hand corner, yellow box, go to the BS FAQs and check out topic 11 - the 180.
You need to give this asshole a little wake up call.
Stop worrying about him and you get yourself together to take care of your kids. EAT. drink ensure or something similar if you cant eat right now. Stay hydrated. Sleep when you can.
Fuck that guy. You take care of YOU and the kids right now, honey.
Do you have any support nearby? Family? Friends?
Oh - and welcome to SI - I'm sorry you're here, but glad you found us.