lost my profits on one race, again

I made a real mess of the 14:20 at Haydock. It was a difficult race to trade, with 2 low priced horses that drifted and came in a lot. So by the time I got near the off, I was down £1.30, did I just take that loss? No, I attempted to trade out, scalp no less, in a very volatile market, made more volatile by the fact that it was near the off, and it was very difficult to predict. So of course I got caught out by a big move right before the off, and had to red out, more than doubling my loss to £3.09. After a bit of shouting at the screen, I got a grip, took some deep breaths, and carried on trading, managing to get back to a profit for the day of £0.80. If I had just taken the £1.30 loss then I would have been on for a decent total for the day. Another hard lesson in when to take a loss, which I will learn from, or die in the attempt!