How to cut off my aunt in a way that won't mess up my family dynamics?

I'm terrified of my aunt and cannot be in contact with her for personal reasons. As such, I've had her blocked for quite some time (about a year). She's a doomsday prepper, a conspiracy theorist, and is generally disapproving of my "lifestyle" (not getting into this, I'm sure you can infer what I mean), and has generally harassed me to the point that I had to block her. well she contacted my dad about it and he asked if I'd been getting her texts, etc. My dad would not understand my point of view, as he has an unhealthy attachment to her. I don't want to mess up my relationship with my dad, but I cannot have her back in my life. What should I do? Happy to answer any clarifying questions if need be. Thank you in advance.