That is a lot, trailrunner. I am sorry things are so hard and overwhelming for you right now!
I hear that you can't take a "big" time out. Is it possible to take "micro" time? Deep breathing while pouring a cup of tea, mindfully counting steps while walking across the room, deep inhalations of baby(?) smell while you snuggle with the little one. Things like taking a moment to feel the chair beneath your body and the floor beneath your feet, maybe momentary sensory grounding experiences might anchor you in the here and now for a little moment or two and help to calm your hyperarousal of your nervous system?
I have had times like that and they are very hard. You have probably had many times like this before too and coped with them as you are now, just struggling to hold on moment to moment without a breath. Maybe just taking a few mindful moments to take those breaths and connect with your body might help to do it differently, to support yourself a little bit more even though you can't take "big" care of yourself right now?
Sorry if this isn't helpful.