worry oneself needlessly; bring vexation on oneself; torture oneself with unpleasant thoughts
Don’t worry/trouble your head about it! / Don’t trouble trouble until trouble troubles you. / Don’t cross the bridge until you reach it.
She'll be coming soon, don't fash yourself.
He said his wife was always fretting her gizzard about something.
Why bother, then?
Reality woke me up when I heard a voice saying, "I don't know why you bother trying to dance.