When I had the problem, I think it stemmed from a lack of confidence in my ability to be a winning trader, time and time again. Until you have that confindence, you will never bet properly. You can get the confidence from trading a system, your own preferably.
Quote from wwatson1:
I find the problem you have comes from discretionary trading, once you have a system that has been tested and shows proven results and is rule based there will be no point in you getting in and out of trades on a whim.
And see the "Brain Kills Profits" thread
(this forum) once you have a system!
My discretionary hell lasted about 10 months and I blew through about 15k. I felt like a loser the whole time, even on winning days (and there weren't too many of those). Now that i'm past it I feel like a winner all the time, even on losing days. It feels really good to have that confidence.
I got out if it by cutting off my trading and spending a few months developing a system. I recommend a longer term system, not a daytrading system if you're going to figure one out. I could never figure out one for daytrading. But if you must check out Woodie's group.
All you need for a system: entrance, exit, stop rules, and bet size. All are equally important. Don't just work on entrance. It's okay if you don't understand systems you read about on the web. I only understand about 10% of them. All that matters is that you understand the one you trade. Best accomplished by making your own.
Also you can have a system that contains some discretionary rules. For example, I can vary my profit target between conservative and agressive (and the amounts come from backtesting). I know that 15 NQ points for the trade is my long term breakeven point, profits increase to 25 points, but a higher profit target might be better, might be worse. 50 points never gave good results in the past. So I get my kicks from setting the profit target. Even when I get scared I never set it below 20. Soon I hope not to be scared anymore.
I still worry that my system one day won't work. But, I tell myself, I'll just trade another one. I don't want to fall in love with this system. But I take comfort in the fact that i'll never go back to that hell. It really was hell, it affected many things in my life in a negative way.