Journalling helps. There are so many ways to do it. You can just dump all your anxieties in the journal, or you can fantasise a good day - a sort of creative visualisation fantasy as if you are already living it (must confess that one doesn't work for me - it feels fraudulent but some people love it) You can make arty bullet journal lists or bucket lists. You can keep tabs on any self care actions - meditation, exercise, healthy food etc.
I find it really therapeutic to make At least I lists in the journal. On days you feel you were a complete washout waste of space you write down all the things you did do, despite feeling low, and discover you fed the cat and the children, went for a walk, cleaned the kitchen or bathroom, ordered something online etc. Small things but they validate your existence. Without them, children and cat would have gone hungry, you would not have had fresh air and exercise etc.
The other fun project that usually lifts me out of depression more quickly then anything else, including medication, is doing something new every day. Anything at all. Just do it and then write about it in your journal - make a note of what it was, how the new experience felt and whether you want to do it again. Can be trying out a new recipe or scent of soap, walking down a new path or listening to new style of music. Or bigger stuff - visiting a new country, applying for a new training course or job etc. Once you start, you get into a habit of saying yes to things you might normally shy away from. I used to do it all the time - stopped during lockdown, but it changed my life in so many positive ways.
I really must get back to doing it.