to make someone feel very tired and nervous (often reflexive) She's worn herself to a frazzle trying to get that report finished.You've been looking after her kids for a month? You must be worn to a frazzle.
In a state of nervous exhaustion, as in The very idea of moving again has us worn to a frazzle. This expression transfers frazzle, which means "a frayed edge," to one's feelings. [Late 1800s]