In my opinion, setting a monthly budget for yourself in order to limit spending money is a good idea, but I try to play gambling is not regular so as not to develop a gambling addiction (as in Pavlov's famous experiment with the dog when the dog has a new conditioned reflex), so my budget is allocated for one game and is no more than $100.
I do follow the same principle that each month on particular month I keep an x amount fixed for the playing or say for fun. If I lose that say on the very next day too than whole month I will be away as cannot input more capital as monthly budget allocated is finished. And in case if win certain amount during that month then that will be my bonus amount. This just helps to be in limits.
You do have a good control with yourself, having that kind of discipline ain't easy to do, there are times that gambling will haunt you.
Times that urgency to play is inside you, letting you think that you can win this time or on that particular events,
it's common that even you set your budget you still feel something that pushing you play and deposit another amount.
But if you do have that focus, then you are good and your chance also to win is better than those who can't control.