Worry is interest paid on trouble before it falls due.

William Ralph Inge (1860–1954) English prelate [Dean Inge]

Sermon (1932-02-09), St. Paul’s Cathedral, London
    (Source)

As reported in The Shields Daily News, "Far and Near: Dean Inge on Worry," Northumberland, England (1932-02-10). In context:

Christ condemned worry as a sin -- perhaps He was the first to do so. And what good advice this was! "I have had many troubles," said someone, looking back on his life. "Most of them never happened." Worry is interest paid on trouble before it falls due.

Though Inge employed the phrase, it was in wide use already, having been crafted in 1905 by H. A. Thompson. See more here: Quote Origin: Worry Is Like Paying Interest On a Debt You Don’t Owe – Quote Investigator®.