We are always in search of the redeeming formula, the crystallizing thought.
I do believe it is possible to create, even without ever writing a word or painting a picture, by simply molding one's inner life. And that too is a deed.
One must also accept that one has 'uncreative' moments. The more honestly one can accept that, the quicker these moments will pass.
We have to fight them daily, like fleas, those many small worries about the morrow, for they sap our energies.