For me, getting active is my go-to. Doing it early (morning) is crucial for me.
Pushing myself physically takes my mind off problems and I focus exclusively on my well being for a little while...mostly trying to stay alive. So for the stress of life, the anxiety of responsibilities and the unknown, the frustration of being out of control of so many critical things, the realization of unmet expectations - all of it it is suspended for a while while I simply force myself to continue existing.
And every time when my brain tells me I can't do any more, I'm out of breath, my knee's can't take any more pounding, my feet are aching, my muscles are sore, it's too hot, I feel a little sick, am I overheating, did I almost just throw my back out, today can be a light day and I can make it up tomorrow, do I need to stop and pee, do I need to stop to get a drink, do I need to just stop for a few minutes and rest...every time I win these battles I gain confidence, I learn to distrust my always-present doubts, that I am stronger than I think I am.
Somehow all of this seems to trickle over into the rest of the day. Sort of like making your bed in the morning, the first in a chain of events of getting things done and caring for yourself.