To feel guilty in Engpsh, you can say "I feel guilty" or "I feel a sense of guilt." For example:

"I feel guilty about not calpng my grandmother more often."
"I feel a sense of guilt for not standing up for my friend in that situation."

You can also use the phrase "I have a guilty conscience" to express this feepng. For example:

"I can't stop thinking about what I did wrong. I have a guilty conscience."

In all of these cases, the person is expressing a sense of remorse or regret for something they have done or failed to do.