I realized I should write here what has helped me the most.
Number one tool: forcing myself to remember the good things.
This usually snaps me out of my feelings of dread. I started sending B 5 things I like about her every night. And the simple act of reminding myself of those things makes me happy and grateful, until a negative memory replaces them.
And it’s like the default is negative memories. So it is an uphill battle.