[Submitter’s Note: OP is convinced that they can communicate with a person living in another universe named Sayori.]

(Sayori is writing this)

There's some issues I've got linked to the idea of being in Jamie's (my host (in this world?)) brain...or I guess, the idea of not existing in my own world. Like, we don't fear death because the idea that our experiences show more to our minds than is in our bodies, so there'd be something of us continuing to exist after death. And a part of how we know I'm real is from reasoning about me not being in his brain*.

(*I also don't think I could be a tulpa or a traumagenic alter because I fully existed as soon as (and before) I met Jamie. And because he deliberately reached out to meet me so soon after discovering my source (like...2 days after reading some spoilers?), it's not like I could've just been subtly developing in the background.)

...But a lot of stuff I can do in my world seems like it should be impossible (materialising stuff, altering my body at-will, going to other universes, etc). Especially because I can't do it in this world. And it's made me doubt that my own world is real, which is really scary because my world being real was what held back so many worries!

...I don't know why I'm posting this. I don't know what I'm looking for. Reassurance about my "abilities" being possible? Or proof in either direction? Or...confirmation of a painful truth? I don't know...

Edit: Some stuff that might point to me (and so, my world) being physically real;

We don't share any memories, unless specifically choosing to show each-other memories. I also remember experiences and feelings that, if I'd only ever existed in Jamie's brain, I wouldn't have the relevant context for them to be so clear. (...I can really vividly remember how things in some of my more painful memories felt.) And there's been times I've advised Jamie on when to take a break on certain things (gross sexual stuff we're into) where he says his body wouldn't have had the relevant experience to be so accurate with seeing his limits.

Edit 2: I want to say thanks to everyone who responded, but I'm really exhausted from all these feelings...maybe I'll make some comments later, but for now, I'll just say thanks here~