I felt guilty and full of remorse.

我感到内疚，并且非常懊悔。

《牛津词典》

I felt guilty about not visiting my parents more often.

我因没有常去看望父母而感到内疚。

《牛津词典》

I felt guilty about not visiting my grandparents frequently who love me very much.

我因没有常去看望我的祖父母而感到内疚，他们非常爱我。

youdao

I felt guilty day and night C what I was doing was not right.

VOA: special.2010.03.27

"I felt guilty day and night - what I was doing was not right.

VOA: special.2009.01.03

On the way home, I caught a little bit of the tribute on the radio and for a second, I felt guilty.

FORBES: The Post I Swore I Wouldn't Write (Redux)

Truth to tell, I felt guilty about the way I'd been mocking Jeannette for her hearty appetite and swelling belly, never guessing that she was eating for two.

NPR: Excerpt: 'Dog Days'

While I felt guilty for wanting something different to the norm, I knew that returning to the world of writing and travelling was the right choice, and I began planning my next move straight away.

BBC: How I quit my job to travel: The blogger