sexual desire, hunger, laziness, fear and greed - these are the forces that turn this world around and you can not do anything about them. What you can do is to manage your risk.
In the cash market without leverage commit no more than 30% of your available funds to such games and you'll be just fine.
Let's say that if I could stop losing confidence when fears appears, I would be way wealthier.
I tend to analyze right, then panic and trash it all just to find I was right in the first place. I guess this comes with experience, and I'll have to wait.
(And yeah, I already noticed that margin trading is a panic/stupid mistake booster)
Right with you, buddy. It stings, but what can you do. Try to learn, manage risk, and don't be too hard on yourself. At least that's what I try to do. Perfectionism and impatience can be quite harmful in investing/trading. All successful professionals say you need a system/strategy, and you need to stick to that with discipline. And play small with that strategy until you start seeing results consistently enough. Mind you, even successful professionals can be wrong 50% of the time -- the difference comes from how they manage downside risk vs. upside potential and results.
All of this sounds quite obvious, at least it has to me. But to actually follow it -- that's seriously quite hard and takes practice. I've also learnt the hard way to protect capital during this learning period. Play small, keep working on your strategy until you have confidence to increase the bets. Yes, it stings to see the "oh, I saw that coming" moments or miss out because you were playing too safe, but if one doesn't have a track record and system based on experience to place the bets with confidence and without stressing too much, at least I've found it's not worth it.
TL;DR -- Having a strategy, built with experience by only risking rather little capital, and then sticking to it when it has proven to work, is the key to successful and emotionally less taxing investing/trading, I believe.