Beside yourself - Idioms by The Free Dictionary
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Very shocked or distraught. I was beside myself when I found out I'd been rejected from my first-choice school. Honestly, we've all been beside ourselves since the funeral.
beside yourself overcome with worry, grief, or anger; distraught.
beˈside yourself (with something) unable to control yourself because of the strength of emotion you are feeling: He was beside himself with rage when he found out what she’d done.