Quatrarius, binder, wasoxygen (?).

Tournament background: you have to make at least 25 moves every hour or you lose the game.

Time situation: I had 18 seconds left until the end of the first hour, my opponent had comfortable 8 minutes.

Style of my opponent: Despite the game so far, I got hold of some of her earlier games and it leaned toward aggressive development.

Mental state: increasingly nagging "I'm going to lose this" combined with "shouldn't have skipped breakfast".

OK, so what I did was

  23. Qf3

Here's my reasoning: I thought that the best course for Black would be to follow up with g4 and continue kingside development. It's a very good move which would resolve to

  23. Qf3 g4
  24. hxg4 …

Now we have a branch:

  24. … f4 debilitates my position and I'd call it as extremely strong (!!) move.
  24. … fxe4 opens the centre for exchanges and would break the terrible stalemate, which is a type of game that I prefer.
  24. … fxg4 is like fxe4, but would be even more decisive. As far as I could calculate it, response/evasion 25. Qg3 wouldn't be a bad position.

Alternate responses I calculated were:

  23. … g4 - block my queen and prepare to make a trap
  23. … Rae8 - gather more material on the kingside, prepare for/deter from centre exchanges.
  23. … Re6 - strengthen e lane, possibly move Qe7 next turn and prepare for an aggressive push.
  23. … Qf7 - poorer version of the above move that unnecessarily risks queen but isn't strictly bad for positioning.

and I got a bunch of branches for each of those moves. Then I got served something that didn't even occur to me:

  23. Qf3 Ne5
  24. Qh5 Qg7
  25. g4 fxe4

Board situation afterwards:

Now that I sit in the comfort of my room, it's not completely lost, but it's really, really bad. Queen has no mobility, my defences are separated and I'm likely to lose material trying to prevent the nigh-inevitable promotion on d line.

What can I say, I got bested. Time pressure is one thing, but I felt like I'm on the ropes since move 8 or so. Despite everything, it was a good game, if not for any other reason that by being a great example of how volatile chess positions can be.