Gambling will always be gambling. So no matter what formula or strategy you will use, you should not expect anything lucrative out of your gambling activities. Because if you start expecting, you will surely get hook into this addictive activity. And be disappointed for whatever outcome you will get and continue playing if you won't get what you want.
Luck will always play a role in this game, so it means, you always have no assurance that you will hit your target in every game you played.
Not expecting anything lucrative is giving up already before you even try. You can make big profit from gambling but to get that you have to believe it before it happens. If you do not believe then you will not achieve it. Gambling is about luck but you are incharge of the decision that you make that give us an advantage to become lucky. If you do not gamble, you can not make money from gambling therefore you have to keep trying with hopes that it will happen one day but still be capable of telling yourself the truth so you do not waste time on playing games that would not give you a better chance of making money. Stop playing games that are stressing you and play those that you will be enjoying while you are gambling because gambling should be fun.