I can only advise on the psychological front.

What I do to keep myself moving is whenever I notice that I’m frozen I start saying to myself “Move. Get moving. Keep moving”

Like I literally say it out loud. If I stay frozen it gets worse and worse, and I know that from experience. So I just command myself to keep moving.

I often find myself visualizing Trinity in the opening scene of The Matrix: https://youtu.be/cGeoB8czHo8?si=xlRzFuM7S8TQzDNU

She’s been kicking ass and moving fluidly, then for a moment her task is vigilant stillness. But a part of her recognizes that the still posture has a danger of becoming a freeze response, so she gets herself moving with words.

And if I break down crying, I limit it. I cry for a bit but, slightly before I feel complete about it, I force myself to get moving again. I allow myself short, finite periods of collapse, but I make sure to cut them off before I get too deep.

This is the system that seems to work best for me when I’m in the most hopeless situations.

Edit: I want to add that I’m a single guy who lives alone. These breakdowns aren’t happening with a partner. All my worst moments have been alone. In a group I’d be composing myself as much as I possibly could to help keep the general mood up.