I'm not an active trader but my brother(whoever I consider brother, whether blood or not)is, what he always says to me is that it's good to have someone in the business by your side some days when taking trading as they will help you during your emotional ups and downs, they can spot the error or your mistakes because they are not the one staking their funds so it's easy and they have no emotion to the trade.

He also further said that, if you're not lossing you will always thing what you are doing is right and best way to get over your losses is to stop take a nap and then get others to looking into your trading confirm your strength and weakness this will always be my top tier of emotional control when trading.