You can't help yourself especially when you win some big amounts. Your emotion is telling you to bet more that you would still win if you will bet more. If you don't control yourself from that situation you might end up with nothing. You might be frustrated when you run out of balance when you already have won some big amounts.
Definitely greed conquered your thought here and your will has given up on that greed. This always happen to those who lack self control. I may not say addicted since greed has more possibility to triggers obsession than addiction. Talking about addiction, this happen when a person rely on gambling to alter his mood and got an impulse control disorder.