if we can't control our emotions, then you will most likely continue your game until you have no balance left which should not be used for gambling, and maybe you will definitely regret it.
Controlling it in theory is very hard to do in actual or else we will be successful or less losses since we can stop gamblin when we loss part of of our bank and same when we need to take profit. Gamblers usually failed to do this because our emotions keeps us for not doing it because are greedy in nature.
At the same time, Emotion is makes gambling exciting and fun if our purpose of gambling is for entertainment. Habing no emotion on gambling doesn’t feel anything even when you win. Your’re right that we need to balance everything to become successful and happy at the same time.