The taste that wakes you up

I'm sitting here drinking decaf coffee at 3 in the morning. I actually made it to bed at a decent hour for the first time in days. Thought I was going to get some much needed rest. But I woke up about 2:30 very disoriented. Tried to going back to sleep but I couldn't remain still for very long at a time. I'm wondering if it's some kind of panic attack. So in an attempt to occupy my mind and try to calm down, I made coffee. Which I rarely drink. But I'm hoping this warms me up and soothes me back to sleep.
I'm a little nervous about tomorrow, my first day of a training workshop in my new job, but not overly so. I can't imagine that's what woke me up and is keeping me up, but who knows.
I want to be exhausted and sleep sleep sleep for the next three and a half hours.