Hello Daniela:
I just brought up a post on smoking triggers that may address why you are having such thoughts today. Hope it helps. For the record, there is no such thing as killer cravings. Craving can't kill you, but giving into a craving, or more accurately, a triggered thought can kill you. Keep remembering this--by quitting smoking you are fighting for your health and your life. Remember why you quit and you will stay resolute to never take another puff!
Joel