Here in the United States, the difference might be shown in this way:
TOM: I hear you were in the hospital for a month. How are you feeling?
SUSAN: Oh, I'm feeling well. = in good health.
MONA: Sorry to hear that you got a divorce.
JOE: Thanks, but I'm feeling good./I'm good. = in good spirits.
RALPH: I just got a $100 raise at work. I'm feeling g