That’s great advice, but you know how addiction works. Money or no money, a gambler will do what they do before thinking of the consequences. OP may think oh £10 won’t hurt out of my budget and then before you know it, the whole lot has gone, and they will be having to transfer money from one bank or another to be able to last the rest of the trip. The apple pay one is a good idea, providing all the shops accept it now, which I’m not sure they do. If a card machine is down too, you’re fudged.
Do you work alone or with someone? If you work with someone, could you not ask them to look after your card for you? The only other thing I can think of, is if you pay for hotels/accommodation in advance, plan for how much you’ll need for food, drink and petrol costs, and just take that amount with you alone. No cards, no extra cash, and that way, you know if you spend the only money you have on you, you’re screwed. Also, I know this wont put you off but think how low the RTP is on those machines. You’re probably going to lose on them. As you’ve said, you’re down even after those £500 wins.
Hope you find a way leave the FOBTs well alone, they all should be smashed up in my opinion, and bring back the £5 jackpot fruities. They were just as fun :p