Supplies that are gradually diminishing are said to be “petering out,” and someone exhausted is “all petered out.”
The expression was used by both Abraham Lincoln and Mark Twain.
It is derived from a very old mining term used to describe a vein of ore that splits into branches and then gradually runs out, leaving the miners and investors high and dry.
The image is of Saint Peter, who left Jesus when he was needed most.
We say that something dwindling is “petering out”.