I would not be standing here today with you, felt with regret.

我今天就不会站在这里，看着你们，满心的悔恨。

youdao

He felt a kind of happiness mingled with regret.

他感到既高兴又遗憾。

《牛津词典》

You were the first person that I had a slow dance with. The first one I 've ever felt this way about. The first I could ever tell such secrets to and never feel any remorse or regret.

你是第一个与我共舞的人，是第一个让我有那种感觉的人，是第一个让我吐露心底的秘密而毫无悔恨或遗憾的人。

youdao

He said he felt "shock, anger, dismay and deep regret" about the treatment of vulnerable people with severe learning disabilities at Winterbourne View.

BBC: Support worker and patient at Winterbourne View