To stick to a strategy is stupid enough for anybody who is "gambling" because strategies and plans don't really work out here.
Take Martingale and other methods including reverse - martingale strategies which were the most profitable strategies unless house found a glitch in it that once you start losing your bankroll x times your current bankroll (where stagnancy knocks the door badly), you end up losing all your capital.
What's your mistake? It's just that you followed something you were not aware of completely. No tricks could make you win in gambling but your luck and skills could make you get "something" out of it.
As you told there is no available strategy to win a gambling bet if you want to win you need to have luck on your side.The gambling is only for the fun purpose but many people will get addicted to it and can't get out from that addiction finally they will lose all their capital.So it is better to understand the situation of gambling and then invest that betting amount in to some other investment with less risk.