気分and気持ちis almost same,difference is very slight 気分（が）悪い＝a)in bad mood, iunpreasurable,feeling creepy, disgusting b)feeling sick c)in bad mood because feeling angry 気持ち（が）悪い＝a)feeling creepy, disgusting, unpreasurable b)feeling sick 気分悪いexplains more broad meaning than 気持ちが悪い。気持ちが悪いusually doesn't include meaning 'angry' Unfortunately, we ourselves can't distinguish these two word, since we sometimes use these as the same word. You need to assume the meaning from whole phrases.