Tā zài yīyuàn děng le yì zhěngtiān, xīnli jiāojí nánnài.
He waited at the hospital all day, unbearably anxious.
Tips
usage
难耐 comes after the thing that is hard to bear, usually making a four-character phrase: 酷暑难耐 'unbearable summer heat', 饥饿难耐 'unbearably hungry', 寂寞难耐 'unbearably lonely'. It is a written word; in speech people say 受不了.