If you're being targeted, can you really protect your domain/DNS from all points of attack? And does domain privacy protection really covers all of your personal data, forever?

The more I learn the worse I feel about my digital privacy and security. The one thing I do right now is to compartmentalize my accounts and services, but I can't help to think it's only stopping smaller fish from getting/triangulating my data.

Tin foil hat apart, I also don't like to give away my data for free.