As has been said, you aren’t wrong.
“I have some worries.”
“I have at least one worry.”
“I am worried.”
“He worries.”
“Why worry?”
It’s used as both a verb and a noun rather interchangeably and there is no particular difference in the root-meaning. Concern is a good synonym yet it also has the same problem in the same way.
It’s rhetorical to define the verb as, “To worry” or, “To worry over a worry”, it just is what it is 