I stopped cold turkey and had a head ache for 3 straight days, then gone. I didn't take any medication, I don't like to take meds if I don't have too. Also, I take cream and sugar in my coffee. I noticed that I now need a morning snack since I don't have that bit of cream to keep me satiated. I drink green peppermint tea instead to keep my that "full" feeling in my stomach and eat a piece of string cheese if I need to. I, too, get the shakes if I have caffeine now that I have stopped the coffee. I find if I crave coffee, I have 1-2 pieces of 90% cacao chocolate (Lindt) and that cures the craving.
I hope that helps.
webbgirl