Its the caffeine. I have the exact same issue and have gone over it with my old Doctor. Either you can cut back on coffee- try an almost full cup then back down to 3/4 cup or 1/2 cup to keep the caffeine in check, OR you can just drink coffee every day and take Tylenol for headaches when you don’t drink coffee. I took option two. Fuck it. I don’t want my biggest regret to be “I wish I wasn’t such a coffee pussy” when I’m on my death bed. DD large, just sugar for LIFE.