Disappointment and pessimism are nothing out of the ordinary, but the other symptoms you describe makes me think it's more complicated than that. It sounds like

Disappointment and pessimism are nothing out of the ordinary, but the other symptoms you describe makes me think it's more complicated than that. It sounds like you might have depression, but I am not qualified to diagnose you. A therapist will be able to provide you with better insights for dealing with this than any of us can. Have you sought professional help?