I'm sorry you're having this experience. You mentioned you struggle with anxiety. And I see you list yourself as living in the Midwest. If the weather where you live is anything like where I live, then it's been crummy lately. Add to that the stress most people experience over the holidays & perhaps the paranoia you're having is a result of a lot of pent-up anxiety.

The other thing that occurs to me is that you mentioned you gave up your conspiracy theories 2 weeks ago. Perhaps you've simply transferred the paranoia you were channeling into your conspiracy theories into other areas such as your visit to your grandparents' home. Of course, I don't know. I'm just throwing out some ideas here. Under any circumstances, I hope you are able to find a way to calm the paranoid thoughts you're having. I'm sure they're difficult for you to tolerate.