in over one's head, to be

To be swamped (with debts, work, responsibilities, and so forth). The analogy in this expression is to being in water over one’s head when one presumably is not a good swimmer. In the early seventeenth century it was put simply as over one’s head, as in “That silly women shall be dipt over head in a Gumble-stool for scolding” (Richard Baxter describing a ducking-stool in 1653).