When I first started trying to quit I used Benadryl to mellow me out before sleeping. It never gave me a craving for Alcohol. Who knows, maybe it did trigger some kind of buzz in you that made you want to hit the 211s. I used to hit the Steelers, two or three before sleep after 10 or so "lighter" beers so I could poison myself into an alcohol induced sleep.
I just am glad I haven't relapsed yet and hope the same for you. If the cold meds worry you, try to go without them.