Drinking dreams!
In a very similar scenario, I recently found myself in a hotel room, having finished a whole bottle of wine and wondering whether to go and get another one. Similar to you, it dawned on me that I wasn't supposed to be drinking at all! WTF!? There goes 2.5 years of sobriety and how did that happen? Panic, remorse, huge disappointment etc.
Then relief as I woke up and realised it was a dream.
Here's to 5 months! Congratulations!