Yes, I have this problem too, but I haven't solved it yet. I can lose a maximum of 300 bucks, but sometimes, when the slot gives me nothing, I get unrealistic anger, which leads to higher bets and aggressive play. 
It seems to me that it makes no difference how aggressively a person who uses a deposit limit gambles. You limit your maximum possible losses, and the probability of winning mostly depends on the algorithm of distribution of winnings. If you are unlucky, then no matter how aggressive were not your actions during the gambling session, it is unlikely to affect its outcome.