You can decide to use whatever amount you want to gamble as long as you dont exceed the amount allocated for gambling. This is why it is advice to always remove a certain amount for gambling weekly or every month. The amount is not going to be fixed because our income can grow so we can decide to change the amount anytime. Inside that amount we choose we can decide to gamble using all the money at once or break it down into several bets within that week. All will work if we are confident on our bet. However, no one can be 100% confident on his bet so i will advice to not use all at once. We can try betting 2 everyday or 3 a day and see how it turns out for us in a week.
Withdrawing part of the money won is one of the best thoughts that can be in gambling, otherwise if you do not do this, we will never make a profit, even from those rare wins that happen in gambling. And if everything happens the other way around and we lose very often, this does not mean that we are losers, it is just that accidents tend to line up in a losing streak, absolutely all players face this sooner or later. The most important question is what reaction the player will have to this event. Taking a break is an excellent solution, because if you do not take it, then under the influence of violent emotions, you can lose all your money, this happens very often.
Yes of course and that is the reason why a gambler must have the ability to stop at the right time, there are many benefits from this ability, especially when they are successful in getting a win, they will also be able to enjoy the results of that luck, so on the other hand I will also say that a gambler should really be able to appreciate the results of victory, we must have the mindset that getting a win is not as easy as turning the palm of your hand considering that luck is something that can never be controlled.
On the other hand, this is also the reason why gamblers must really know and understand how winning and losing work in gambling, and yes I also agree with your suggestion in your last statement that taking a break is the best solution in any situation, especially when you experience defeat, this will prevent you from emotions and various actions out of control.