I'm in a similar position, and lately I've been having flavored sparkling waters (Mmm Orange Bubly) and herbal (i.e. non-caffeinated) teas, depending if I want hot or cold. Obviously they don't taste like beer, but what I found was at least for me after doing it a while, it's not really the taste I wanted; that was just the association I had with the ritual I enjoyed of a nightcap, and now I'm happy with my new ones.