I also used Benadryl for sleep, but the lingering hangover when I woke up lasted for hours. Kinda felt groggy til noon. I now use melatonin. I do recall having vivid, disturbing dreams. Too high of a dose does cause heart palpating, atleast in me it did. May I ask, how many mgs are you taking and at what time in the evening do you take them? Many chemicals cause cravings, this one made me think. Wishing you well, Twofish