Akademik

небо в овчинку кажется
• НЕБО С <B> ОВЧИНКУ КАЖЕТСЯ/ПОКАЗАЛОСЬ кому highly coll
[VPsubj; usu. pfv; usu. this WO]
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⇒ (in refer, to a short-lived, intense sensation) s.o. experiences extreme fear, intolerable pain etc:
- X-у небо с овчинку показалось{{}}≈ X thought <felt like> he was going to die (on the spot);
- X felt as if the sky were about to come crashing down on his head <on him>;
- X felt like the world was closing in on him;
- [in refer, to fear only] X was frightened (scared) out of his wits.
     ♦ "Струсил ты, признайся, когда молодцы мои накинули тебе веревку на шею? Я чаю, небо с овчинку показалось..." (Пушкин 2). "You got scared, didn't you, when my lads threw the rope around your neck? Frightened out of your wits, weren't you?" (2a).

Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. . 2004.