Mortification is the sharp feeling of being extremely ashamed, embarrassed, or offended — the kind that makes you wish the floor would open. “To my mortification…” is a set way of telling the story: something happened, and the shame hit. It is a rather formal, even slightly old-fashioned noun; younger speakers more often say they were mortified, using the adjective. Though actually the word has older lives, which is why it feels so heavy. In religion, mortification of the flesh meant punishing the body to tame desire. In old medical English it could mean a bit of the body dying. Those uses are rare for learners now, but they sit behind the shame sense: the feeling is talked about as if something in you has been struck down. For the sense you will meet in everyday English, keep to that deep embarrassment.

羞愧難當、無地自容（指那種強烈的丟臉感；日常更常說 I was mortified）