feel bad.
The German phrase "sich schlecht fühlen" is the equivalent of the English phrase "feel bad". It is used to express a feeling of discomfort, unease, or dissatisfaction. This phrase is often used in conversations to express one's emotional state. It can be used in various contexts, such as feeling unwell physically, feeling guilty about something, or feeling sad.
I really feel bad because I did not do my homework.
This sentence is by a person expressing a negative emotional state, due to not completing their homework.
If you feel bad after eating, you should perhaps go to the doctor.
In this sentence, the speaker advises someone who consistently feels unwell after eating to consult a medical professional.
He admitted that he felt bad after he had cancelled the lecture.
This sentence conveys a person's feeling of discomfort or regret due to canceling a lecture.