Your unexpected expenses are not that much different then mine have been over the years. I’ve used credit cards for over 30 years and never fallen into such a debt trap. When a particular credit card issuer would notify me that it was unilaterally changing terms (and this did happen at least twice), I would respond by canceling the card and moving to a different issuer. My credit rating was such that I never had trouble moving to a better deal.
It was a hard lesson that I have never forgot nor forgiven.