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.
It's true that controlling emotions is very difficult, but it's not impossible for you to reach the point where you can get mature emotional control, of course this requires long training in the journey, it's impossible to happen if only once or twice then you can control it, you need to try many times to get to that point, and I believe everyone can achieve it if you really want it.
Gambling is actually simple and you won't consider this difficult if you are already in that position.
Even though I think I can control my gambling, sometimes I also get out of control, and that is a natural thing, but on average I am able to control my emotions in gambling.