Please consider keeping careful track of your gambling-related expenses and winnings. Maybe carry a small notebook, or enter them into your phone. After some time, you can graph the results pretty easily, and this will give you a clear and honest picture of what's happening. When you work from memory alone, it's easy selectively remember your successes, as these are the most exciting results. So don't attempt to record past results, start fresh from today.
At the end of each month, you can decide whether the fun you get from gambling (and hell, it can be fun) is worth what it is costing you.
That said, if you don't want to know, that's totally fine, too.