Nerve-racking (adj.) - Causing stress or anxiety.（神经紧张的，伤脑筋的）
Examples: 1.A nerve-racking situation or experience makes you feel very tense and worried.
2.His driving test was a nerve-racking ordeal.
Dwell on/upon sth (phrasal verb) - To keep thinking or talking about something, especially something bad or unpleasant.（老是想茤彖芺蚻Y事，纠结于某事）
Examples: 1.Old people often dwell on the past.
2.He tends to dwell on the negative aspects of his performance.
Envelop sb/sth in sb/sth (phrasal verb, often used in the passive) - To wrap someone or something in someone or something.（笼罩，包裹）
Examples: 1.The whole city is enveloped in haze.
2.Mountains of fog rolled in and enveloped the house in dense vapor.
The long arm of the law (idiom)–The ability of the police
and the legal system to find criminals and punish them.（恢恢法网）
Examples: 1. You can't escape the long arm of the law.
2.The long arm of the law is going to tap
you on the shoulder someday, Tom.
A/the sword of Damocles - 达摩克里斯之剑。