Let's face it...
mental or hard, stop losses that are strictly enforced are the only guarantee you have that you will be able to participate in the earning opportunities that markets offer you another day.
Losses are nothing more than a cost of doing business as a trader.
The single most important reason most people are net losers is because they never learn to accept that losses are part and parcel of trading.
One of the most successful traders in New Market Wizards, Bill Lipshutz, was "right" in his trades no more than 20, 30% of the time, which did not stop him turning in one of the top net performances at his bank for years and years.
Let go of the individual trade as the absolutely meaningless event that it is, only focus on your long term edge, let go of wanting to be right, and concentrate instead on wanting to be as net profitable as you can.