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.
The biggest problem is that you do get moments where you have outbursts as in these moment you go crazy and will bet crazy. Similar as you, most of the times I can control my emotions but sometimes everything is going bad and that are the most tricky moments as in those moment you can loose your whole bankroll. I limit myself by having low amounts on the casinos just to avoid loosing too much money when I get out of control.
It is important to notice those outbursts are short lived, so if the amount we have at the casino at the time is on the low side then the damage that we can make to our finances when we are in that out of control state is limited.
So it is key to keep a low casino balance with enough money for a few sessions, and while it would be optimal for ourselves to never lose control, in the case it happened we will still limit significantly the amount of money we could lose during those moments.