I know your situation so well. I self excluded me by nearly 300 casinos worldwide. Until i played on russian sites cause nothing else was left. I know your fear to talk to your girlfriend about it.
I had hide this problem over 5 jears completly from my boyfriend.
Until i diceded in one morning when i woke up and was instantly crying, that i tell him about it. It was no concious decicion, it was uncouncios in the desprerate state of crying.
I took my phone and wrote the whole story down with all details and sent it to him without reading once again.
He was very sad about the fact that i hadnt come earlier to him with this. Since this time, our relationship is much more real and intensive.
When youre hiding something, your partner will feel it. Maybe not concious but unconcios. Especially when its a woman.
Ask your self whats better, be authentic and show who you are, or building an illusion for her.
To stand your ground and putting off your masks, will give you the strengh to start in a new direction.
When you would live a honest life, you need to take that risk. In case she might leave you after all that, she might also not love you enough. But then this relationship might end in every other case sooner or later.
I think its probably more realistic that she stays by youre side, when you really do your best to fight against the problem and look out for solutions.
One thing that helps me, is to give my money away or block the online pay function of my card,
but you can still get paysafe cards in supermarket (🙄🤔 oh i know this so well..)
But you will feel whats to do when you are really honest to your self. I hope you do well. My best wishes, thanks for reading