Why you shouldn't play with your exit points

Here's a trade I made Wednesday, this is the EUR/USD 15 minute chart. Note that this is forex and not the stock market, I'm not going to talk about forex except for looking at trades like this one.

www.freestockcharts.com

I shorted the EUR/USD at the red arrow and bought back, at a loss, at the green arrow (right at the top). I shorted as a preemptive move on what looked like a head and shoulders pattern. It turned out I was right, if I had held onto my short I would have made 100 pips, about a 45% return.
Where did I mess up? Two places, mainly. First, I shorted before the head and shoulders confirmed (I marked that with a line and a "1"). Second, I closed the trade from panic because of what was, at the time, a strong up move that looked like it was going to break the 100 period MA.
What should I have done? I should have waited for confirmation, I got in too early and wasted time holding a sideways position. The biggest thing though was that I shouldn't have touched the trade after I placed it. If I hadn't touched it my SL ("2") never would have triggered and my TP ("3") would have ended the trade at a rather nice profit.
I think bad trades are more important that good ones. They teach you how to be a better trader. In this case it wasn't that my targets were wrong but my mentality. I was worried that the position was going to go in a bad direction so I closed it early. When you trade you need to be able to ignore your nerves and follow your analysis. Every trade you place should have a defined TP and SL, you should go into the trade thinking "I could lose my SL or gain my TP and either result is fine" rather than thinking "I can gain my TP but I'll close before losing my SL". If you close every trade that makes you a little nervous you'll end up with no money left.

As I said, I won't be talking about forex too often here. I wouldn't recommend that anyone trade forex without a large amount of trading experience, it's far too risky for the possible reward. Still, it makes for a good way to test trading strategies due to it being open 24/5 and moving fast.

If you have a stock you want analyzed leave it in the comments. 

Do not trade forex you will lose everything; probably. I almost always have some sort of position in EUR/USD.