Thanks to each of you for your responses. As it turns out, the topic of our D and where H was was not brought up too often and when it was I was able to handle it with dignity and people respected that the party was not the time to get into too many details. D5's birthday party was a great success and she had a blast.
I did speak to several family members about the situation during the weekend (I had a house full, I think there were 11 here overnight!) and they fully support me and standing for our marriage. The overall reaction is one of shock (You guys? If ANYONE is meant to be together it is you!) and agreement that H is in MLC. They are all very religious people as well and they are praying for us to reconcile. It is nice to have support from both sides of the family.
H will be here later in the week to spend time with the kids. I am looking forward to seeing him and going to the pumpkin patch together and also dreading the very likely reality that he will want to spend as little time possible with me. He's told me that talking to me and seeing me hurts too much. It's going to be weird and hurt to be in town and have him take my kids without me. Last time I went out of town so it was easier in a way.
My goal this week: Do SOMETHING, proactive for ME and only me.
Me- 40 H- 41 S8, D5, S4 M 19 y T 23 Bomb drop 6/2013 H asked for/filed for D 9/2014 22 yo OW discovered 9/19/14 they're engaged and living together