The casino is usually the last one to blame, if we want to be honest to ourselves. No one is forcing us to deposit, nor to place the bets. Unfortunately, the concept of gambling and the games themselves are addicting, there's no denying that, we've all fallen a victim of their tactics some way or another. This isn't an excuse though, but as I said, I'm quite confident that we've all have experienced what the OP described.
Where did you fall victim? The part of the human being that is greedy it is the only one you should blame why you become addicted to gambling.
Imagine a kid who is addicted to a game on the phone every day. The kid keeps playing that game to grind something; isn't that the same as how we gamble? This is what I think most people think too. They want to grind, but after gaining a good profit, he didn't stop because he is greedy. He wants to make more, even you already have more than 100% of your capital. Casinos didn't hypnotize as ourselves, just hypnotized by fun. Look at these kids who are always playing. Do you think the kids are hypnotized by the game?
There's no difference between gambling and playing a normal game. Adults, like us, are bored playing phone games unless there is a bet or we gamble; unlike children, who are addicted to playing phone games; they are not bored and invest in a game without thinking about the returns.