I used to have dreams about doing my drug of choice and I would wake up literally waking up and thinking "I can start over tomorrow" or something along those lines. Dreams can really be vivid, but once I realize it was only a dream I usually thank God that it was only a dream and that I am so grateful to be waking up sober.
It was harder to handle in the beginning of my sobriety since sometimes it would trigger me but they will become less and less with the more you spend your days focusing on your recovery and when the cravings are not often if at all- At least this was my experience.