If thoughts of self-control are constantly flying out of your head during the game, you can make a big note to yourself. For example, draw something large and bright on a piece of paper, it can be the word “Stop” or some symbol that will immediately remind you of control. And while you are playing, this note should always be in your focus. Accordingly, if your brain learns to react to the note in time, then there will not be any serious problems with the game and you will not have to over-emote. That's the idea.
Quite an effective solution, that can be neglected by an inattentive player. Different players have various reactions to losses, and they're people who don't get moved by what is written on the wall. Their concern is mainly to get whatever has been taken from them by the casino. Other alternatives could be a voice reminder that could be set on phone to tell the player reasons to stop the session. Maybe few minutes or hours into the game, the alarm, inform of a voice rings and says things like 'you'd lose more if you continue playing'.
One thing that I can think of is just to deposit that you can afford to lose. So it is easy for you to manage the emotions because you know that amount can be totally wiped out after your game. Because once you deposit a loaned money, you will surely, be agitated throughout of your game.
Each player has their own approach on how to remind them when to stop. But if you don't want to be bothered by such kind of reminder, then, depositing the amount that you can lose is one way to do it. Once it is busted, it means, you need to stop. Call it a day! Quite simple and very straightforward!