I feel awful about forgetting her birthday.

我忘了她的生日，感到很难过。

《牛津词典》

I feel awful whenever I make a mistake in whatever I'm trying to do.

每当我在尽力去做的事情上犯错，我会感觉很糟糕。

youdao

I feel awful. I have a terrible toothache.

我难受极了，牙痛得要命。

youdao

Mr. Greiner: I unashamedly am interested in trying to get to the heart of issues and I don't feel that boards add an awful lot when they get remotely into detail because they can't.

WSJ: Nick Greiner: Laying the Groundwork for Growth in Australia

In the grocery store, listening to the same talk over and over, I began to feel a superstitious fear, the presentiment that in these endless discussions something awful was being hatched.

NEWYORKER: Vast Hell