Please help, large snake dream, made me feel sick i woke up. ?

the snake represents your boyfriend, or at least your feelings about him. The Croc represents a primal force in your psyche that has subsumed the feelings you have for him. I think you likely felt sad and sick because you are recognizing the death of your feelings for him. If he was not a good person in your life then you might also have the feeling of a near miss, or a danger just avoided.