섭섭하다 (a) = disappointed/sad for 1) being mistreated by someone, 2) missing something good or having to part with someone you like, etc. 실망하다 (v) = be disappointed (in most senses of the word). - 이럴 때 안 도와주시니 섭섭하네요 = I'm disappointed that you're not helping me at a time like this. - 거의 다 와서 우승을 놓쳐서 섭섭하다 = I am disappointed that I missed the top prize after coming so close. - 벌써 헤어져야 한다니 섭섭하네요 = I am saddened that we have to part ways already. - 난 너의 행동에 실망했어 = I am disappointed with your behavior.

실망하다 - the fact that you are disappointed 섭섭하다 - emotional effect that you feel from the disappointment