And they look at you with disgust

They have no claim to what's yours.

They have no right to look at you with disgust and you have no reason to feel guilty. You could say "I don't have any money to give away"

I use the very specific phrase: “I do not have any cash.” That generally does the trick. No ones busted out a square reader on me yet or asked for PayPal- but if they did I’d tell them I wasn’t comfortable with that.