I don't think you can still be a responsible gambler even though you lose too much money on gambling.
The way I see it, you can be a responsible gambler only if you don't lose more than you can afford to. Losing too much money means you are pretty addicted to gambling. There is no way I can view this as being responsible. It sounds more like an excuse.
If you are losing money regularly, then you should not be gambling in the first place. But you need to analyze your condition after a while. The house advantage is usually 1% or 2% depending on the casino. So if you are playing a game with 50% chance of win, you should at least win 4 out of 10 games. If it is like 1 out of 10, it is time to take a break and admit that it is not your lucky day. If this can't be done easily, then another way to follow it is not to carry too much cash to the casino. Take only limited amount of cash and don't take your credit card along. Once the money is finished, you won't be able to gamble again.