I used to play dice in online casinos and apply the martingale technique. In the beginning, I had some profit but as the time went by I started losing and losing and I wasn't able to cover my initial bet.
Now I am trying something like the same but differently. I pick a big football club and I bet that it will lose. If I lose my bet, I double it and so on.
Sorry about your losses but I guess, that's one of the risks that we have to take on gambling. Sometimes we win, sometimes we lose. By the way have you tried Slot of Money in Vegas Casino (
https://to.crwd.cr/smtm)? The profit is not that much and so is the loss plus it's really enjoyable too.