Sorry you are feeling unwell. I had a cold near the beginning of the Covid situation, and remember feeling poorly, but also lucky because it wasn't Covid.
Yes I know what you mean about ruminating pointlessly, it's usually something I can interrupt now, but feeling unwell can make it harder. Actually I was awake early and just starting to ruminate, partly because we are currently doing some work on my mum's house and spending time there with her. Family is what it is I guess. Many don't achieve the happy togetherness that we yearn for. Yours has been so abusive and toxic that you are bound to feel the distress of that sometimes. You have done a great job of separating yourself from all that, awesome, keep it up.
@Suzette made a great suggestion to just distract yourself away from these thoughts, which does get easier I find, over time, but feeling unwell can undermine that. I want to play the video she's posted but it's 5am here so I better watch it later! Curious to see how those elephants react to the piano.
I watched a long video of one of the Harry Potter films being filmed, recently, it was very absorbing. I just came across it on U tube. It's impressive how they keep in character with just that green screen there.
Also have been watching programmes about cattle farmers in Wyoming who are finding dinosaur fossils on their land, as a way to boost their income. Fascinating. They find mammoths too, just to keep the elephant link... they are more fragile to dig up, because they are more recent and haven't fully fossilised or turned to stone.
Hope you got some sleep. We have a product called Vic vapour rub that helps with breathing, maybe called something different in the US, that can be comforting to use.