SPM -- Sorry I didn't comment on your kids snow day yesterday.
I'm proud of you for taking the chance to offer to help with the kids on their snow day especially since you were unsure of what response you'd get.
However, remember the DB book says we are completely correct in contacting our partners when it deals with our kids' well-being. So good for you for making contact.
I'm sorry she shut you down and I agree that you don't deserve to be shut out of their lives. Don't ever let anyone tell you different because regardless of what happens in your marriage, you are always entitled to be a father to your children.
Hang in there! Keep fighting -- NEVER GIVE IN -- and remember you are worth it and you can and will get through your Hell. Keep going and don't turn back now.