Finally experiencing the opposite side of variance

Having my first rough day in a while. I had a few tough pots at 200NL 6 max, and was down 2 buy-ins. I challenged an over-aggro donk (who stacked me in a coin flip) to a heads up match. He said 2/4 and I was more than happy to oblige, I felt just by spending a half hour at one table with him that I had an edge. Challenging people to HU is fun - it's the way dorky internet players (and I am one) challenge each other's manhood.

Anyway, we got down to business. He is very aggressive, and C/Red my continuation bet at a ridiculously high frequency. We were about even, when this pot happened. We played for another half hour or so after that, and then he quit on me, still up a buy-in. I'm down $815 so far today. According to my equity in all-in pots today, I should only be down $92. Oh well. That's poker... the same poker that has awarded me many pots that I didn't deserve in sessions past.

In the past, during sessions like today, I'd either get depressed, or just get angry and continue to play on tilt. I felt like I maintained my composure today, though... which makes me happy. Being able to quit when you're starting to tilt is very important, but even more important is to maintain emotional stability (so the tilt never happens in the first place).

Gonna try to log a long session or two tonight, after I eat dinner and get some light exercise.