LONGER THAN I EXPECTED IT WOULD BE BUT STILL WORTH THE READ.
In my humble opinion, this is clearly a psychological problem and not a system or strategy issue. I have a couple of recommendations, if followed could yield the necessary results.
Phase 1 (I can almost certainly say it would yield the desired result).
1, Read The Disciplined Trader by Mark Douglas. He speaks and outlines the necessary steps to tackle this problem specifically. Trading Trauma due past trading experiences and what not. The idea is that you’ve developed limiting or daunting Beliefs & Associations with trading that inspires fear and set of behaviour under certain conditions. This book alone would be equip you with what you need.
2, Read the chapter on Dr Van K Tharp (pg 411 - 430) from the Market Wizards by Jack Schwager and follow up with Super Trader by Dr Van K Tharp.
Phase 2 / Alternatively!
1, Cut down your position size. If you cannot put on a trade and leave the screen without feeling anxious, you’re either not confident in that trade or you’re risking too much. This would cause anxiety and urge you to get out or secure your profits asap.
If you still want to use your 0.5 lot size. Then learn to effectively trail your stop loss. Either trailing to minor or major zones, swing levels or at the lowest wick of every 3-5 candles. Whatever works for you, but there’s an effective way of doing it otherwise you would just get stopped out sooner than you might desire.
2, Trade on a higher time frame. The benefit of this is a reduction of market noice and arguably better quality setups. This might permit you hold your trades longer as the volatility in short time would not be as overwhelming as it could be in the lower time frames.
3, Do not be married to the idea of a high win rate(I’m not saying that you are, just food for thought). A high win rate does not directly translate to profitability or better still - consistent profitability. If you fundamentally cut your trades short when you’re in profit, you’re most definitely going to have a high win rate. What you might find helpful is increasing your risk to reward ratio at the expense of your high win rate (this is easier to do on higher time frames than lower timeframes) and could effectively improve your profit margin and equity curve.
Pay attention to the highlighted bits on the screenshot, it’s from The Disciplined Trader.