Good maen everyone!
You are right about potassium. I've mentioned a dietary supplement because pills or things like that can have concentrated Potassium and other things, being more efficient. Normally I would just recommend eat more bananas, but with cramps that last that much...
Otlan, Mexicans have a version, which I didn't like that much as ours. Cubans have a better version, or so I was told (I've never been in Cuba). So if you find a place selling Mexican or Cuban food you may find something like that.