That is simple, just accept it, if you lose do not be sad, do not lose hope, just accept the fact that you have lost your money, but accepting is not enough, you to do something to give back the money you have lost. Learn from your mistakes, the good thing to do if you lost from trading is to learn ways and skills for good trading, there is no 100% win rate in trading, so do not think that if you acquire good skills on trading you will always win, it will only lessen the chance of losing. There are many tutorials on youtube where you can watch to be goodd trader.
I had set some rules before trading so I know how much I can loose it or have capacity. Also I have a stop loss always set so that even it triggers it is a limited loss . In trading , one always can’t make money and you will incur losses as well and should be ready for it .
That's great! Rule no. 1 in trading "trade the money you can afford to lose" you have to accept the fact that you may lose your money on trading.