Glad to hear things overall are improving.
Suffering envy/sadness over Sam's pregnancy while you still are in the stages of grief
for your own lost daughter/miscarriage sounds normal to me. You feel what you feel when you feel it. Just give it time and take it day by day. Mourning is what it is.
Not sure what to tell you about G. If you haven't done anything wrong in your conduct? Let him own it. If he's creating a fusspot, step away. Do not engage. It takes two to fight -- let him fight with the air. You can tell him you will not participate in crazy arguments. When he wants to talk to you to do conflict resolution
, he can let you know. But if he just wants an audience for fusspot that goes nowhere -- thanks, but no thanks.
Carry yourself with self respect and expect them to meet the standard bar.