That sucks. I had a 3 or 4 day stretch where I was getting a minor headache late in the afternoon right before NYE. I couldn't explain them, glad they have stopped.
My first couple of mornings after NYE my morning coffee also made me feel worse instead of better. I skipped it for a few days, and now it seems fine.
As far as dry January is going. I've made it through this week. Last night was a challenge. It was my last day of being on the road for work, and I had a pretty good day of meetings on Thursday. I definitely wanted to kick back at my hotel last night. I was hoping I could catch a movie to entertain myself but the theatre did have any late enough showings.
I quite caffeine April 1st and had massive headaches for about a week. I was really on it bad though. I only drank Monster Energy drinks and water all week. LIke 5 a day. I knew it was horrible for me. I was drained of energy until my body corrected itself about a couple weeks later. I had one energy drink last week just to see what it did to me. It absolutely made me jittery and I could not sleep later in the night. So Yeah it was a good choice to quit them.