In his book The Stoic Challenge: A Philosopher’s Guide to Becoming Tougher, Calmer, and More Resilient, William Irvine says “do what you can, with what you've got, where you are.”
Some days you’ll have an abundance of resources; other days you won’t.
Some days you’ll feel like you’re in a good spot; other days you might feel crappy.
Some days you’ll lift mountains; other days you’ll barely be able to lift a finger.
Regardless of what combination of resources & circumstances you’re presented with on a given day, the directive is unchanging: simply do what you can.
Instead of punishing yourself when you fall short of some standard that you’ve set for yourself, remember some days will inevitably be easier than others.
This doesn’t mean anything is wrong with you, it just means that you’re human.