Yeah, other than freezing credit, there's not much you can do. It's a toothpaste out of the tube scenario. It's basically too late. The offerings always suck and are basically only there so they can say they're doing something for you.
Other than that, harden your privacy in general. Yeah, it doesn't help for breaches like this because you can't hide from your doctors, but simple things like having an alternate email address makes it a tiny bit better.
Does Apple encryption encrypt it from Apple? I legitimately don't know the answer to this, but I doubt it. Proton can't see your data even if they wanted to.