Losses shouldnt be a problem if one is using good risk management
Rule of thumb a professional investor (or professional gambler) will limit their losses to 1% of total bankroll available
With a max of 5% loss once in a lifetime.
You need to have risk management, but at some moments (and it will happen with almost anybody), you will have a very bad streak and the first instinct will be to win it back. You want to win it back quickly and will make risky and higher bets than usual also... I think almost any gambler have been there; it happens to me still from time to time allthough I always know it is not the way forward.