Your w described her depression to a "T". They have no feelings for anything and their empathy chips are very broken. I know that it was hard to hear her say this, but it's true for her and how she's feeling about the herself and the world around her at the moment.
If she continues to complain about dog sitting, set up a back up plan. In fact, I would do this anyway. It would provide her w/a view of you taking care of things w/o her having to be there to do this.
I think the vm change hit you a bit hard is because you and your w were getting along and things appeared to have been settling down just a bit. Even though you've been keeping your expectations low, you still were expecting her to keep things the same way, i.e., her married name vs. maiden name. They go through a lot of changing up on things because they truly do not know what they want and what makes them happy. She'll change the vm again before it is all said and done.
Try to keep the focus on you and your children.
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.
