It was an agonizing twenty minutes wait for the results.
Agonizing decisions and choices are very difficult to make. He now faced an agonizing decision about his immediate future
ago·niz·ing in BRIT, also use agonising1. Something that is agonizing causes you to feel great physical or mental pain. He did not wish to die the agonizing death of his mother and brother + agonizingly ago·niz·ing·ly Progress was agonizingly slow