I try to remember to think of the practical view of things first..
I check the "Life Basics" first when I am having a down.
To do this and not have to rely on my memory, I made up a chart on white cardboard and put it on the wall in the kitchen where I can see it.
It is a list of what others see as a normal foundation for life. Drinking water, seeking out and buying food that makes me want to eat it and is tasty and colourful, moving in some way, any way, that day. Walking, stretching, punching the bag, sleep, shower, clean hair, clothes.
The simplest of things that make us all who we are. I even wrote down the kind of clothes that make me feel good. Soft fabric like rayon/viscose, soft cardigans, flat ballet slipper type of shoes.
When I am down I always find that one of these things has not been part of my day or the days before I went downhill.
It sounds trite, but it is comforting to see there is a link. Nothing has to be done in a special way. I can't do gyms or running or wear special exercise clothes. It makes me feel pressured. Just walking to the supermarket and wandering to find a food that makes me take notice is a good way to think of health without the pressure.
Consider putting up a piece of cardboard and keep a marker pen near it so you can write stuff down when you think of it. You will be surprised how it becomes clear.
I think we also don't realise that it is a daily struggle to manage our brains and there are times when we need to be alone and do nothing. The trouble is, the old PTSD Monster tells our brain we are going downhill and the Fear Monster tells us it might last a long, long time. It is good to practise saying the opposite.
"I need a quiet time today in my house watching some trashy, mindless tellie and having a afternoon sleep".