JujuB, of course you are going to be emotional. Why would you not be? You are going through something that only a sociopath would not be emotional about. Don't beat yourself up over it, recognize it and use it as fuel to take a step forward... or two. May I ask what GALing have you done just for you lately. I see that you are helping with your friend's wedding.... but what have you done just for you to make you smile? And how often do you do things just for yourself?
IMO the more you take charge of your happiness the easier it is to drop that rope. However, I also strongly believe the more you think or focus on the dissolution of the marriage the more you get sucked into that abyss of depression and sadness. The physics principle (and Nike commercial) a body in motion tends to stay in motion. Well if you start making yourself happy I truly believe it will become a habit, just as if you let the sad thoughts infect you they can eventually consume you.
As for taking your dad to mediation as long as it is for support, I do not see a problem with it. He should know he is there for support not to advocate on your behalf.
Me 41 W 33 M 2013 Suspect A 11/15 Confirm A 1/16 She moved out 2/14/16 Stepson 13 Stepson 16