I had this problem, great paper trading, but an irrational fear the act of actually trading would somehow jinx the strategy. However, it had to be done and the first time I finally pulled the trigger, I automatically entered my stop based on max loss per trade and watched the trade turn against me and stop me out at a loss of $1200 rather quickly.
I said to myself, "Well, that was a bust", got some coffee, came back and watched the chart until it pivoted off the next support level and traded again. This time I made $3800.
1. Choose the worst case scenario you're willing to accept on the trade
2. Pull the trigger and lock in the trade at the worst case scenario
3. Win/win situation results because you've emotionally accepted the possibility of a loss in advance and you know you'll live to trade another day.