Although a person gambles for entertainment, when he loses in gambling, he cannot console his mind easily because financial loss is a very serious matter. And people can accept loss according to their weight like if a billionaire loses a million dollars he can easily accept it but if a person has total assets of $500 then even if he loses $100 he can't comfort his mind and he will suffer a lot. And that's why everyone should gamble according to their abilities and follow the limits for gambling to be used as complete entertainment.
This is the reason why gamblers should only risk what they can afford to lose.
It's a tough mental game when we talk about regrets. If you know it to yourself that you can't really risk so much, then don't do it just because you feel like you're going to win and you'll eventually take it back anyways. After all, there is no guarantee that you will really win. Everything is uncertain until it's not, so wait for the time that you actually have the winning prize on your hand instead of having an advanced thinking. Remember, we shouldn't count chickens from unhatched eggs.
If a hundred dollar is a big amount for you already and you can't afford to lose it to have it, then stop right there. You can only cry once you lost, but crying over spilled milk won't really do anything good. Hence, preventing it from happening by proper risk calculation and by only betting what you can let go will really help you from not experiencing anxiety because of consistent losses.