Don't beat yourself up! It's okay. You love/loved this woman for many years and had children w/her. You can't turn your heart off and on and it takes lots of time to get over someone, especially if the loved ran deep.
I am glad you went and you reconnected w/your XSIL and you were courteous to your former MIL as well. It shows that you have class. As for the former MIL, no one knows what your XW told her about the situation, but I'm glad she saw that you came and spoke to her other daughter. Tad, try to remember...you did nothing wrong.
I think you have come a long way and I am very proud of you for going to the party. I'm sure your son and girlfriend were happy to have you there as well.
It's a new day, pick yourself up, dust yourself off and continue moving forward. You did great!
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
