"Hope would fail me in the falling snow And slake a wish inside" - The person in the song is depressed. His (I will asume the person is a man according to the last bit of lyrics) life situation is in a bad shape. He tries to hope for the best, but thinks that it doesn't get him nowhere. Falling snow = his current situation.. he can't see the direction his life is going. He doesn't try to hope for the best.
"Friends would leave me in my darkest hour, yet trust me with their lives" - He is trustworthy, but hi friends are not. Another example of his depression.
"She would haunt my dreams and feed my demons They tell me to go" - He is in love with a woman. The man thinks about her (she would haunt my dreams) & the woman angers him for some reason (feed my demons). The man tries to forget about her and forget the hate. (they tell me to go - he is talking about the demons)