He was in a daze.

My heart skipped a beat

She could not believe her eyes/ears.

My eyes widened and my jaw dropped.

Her eyes grew as wide as saucers.

I was shocked like a deer in the headlights.

She clasped a hand over her mouth to stifle her gasp.

He pinched himself to make sure he was not dreaming.

His mouth hung agape.

I asked in disbelief.

Upon hearing the shocking news, I stood transfixed.

His eyes widened in surprise and his hands flew to his mouth to stifle a gasp.

Her eyes nearly popped out of her sockets when she heard the devastating news.

Julia stood rooted to the ground, her eyes widened in disbelief.