Stress-related.

I tend to be a creature of habit, for my sins. I have a dangerously-obvious caffeine dependency and can't function without it. I'm a total stress-head and it tends to get to me. I've spent the last week feeling really ill and suffering with it, right on cue, just before I'm due back at uni. Today was my first day back and I'm exhausted already. In need of a coffee, or a vodka. Whichever someone hands me first. Second year is going to be harder than I thought.