That is actually what I ever experienced, losing more, and gaining less in gambling. That is why I quit gambling. Because until now, I am still confused about how to be in the gambling well. I tried to learn about the strategy of betting and the game that I participated in. But I fact, I still lost more. I feel so dumb 
If you just playing like those who want to only earn and think can beat the house edge and think they are lucky then its fine you may make some money but on other hand numerous ones will end up losing and if you are ready for it and playing for just to have a good time then it should not really be worrying anyone because you know the fact that its easy to lose than actually to win in gambling.
Maybe my advice is just play whenever you have the money to spare, in that sense you will be able to just enjoy the game. I win more whenever I enjoy the game, I don't know but maybe I am more relaxed so I can think clearly. If you would just allot a certain amount of money every single time you play, then losing it would no be as painful compared to when you lose a money meant for something else.