How I see it right now is that there is no way to know what is really real. This is only my opinion, but I see reality as a consensus, there is a norm about what should be real or not. There are people who are psychic and are completely fine and happy and what we call functional, and their reality might be different then mine or yours or from another psychic's reality. And yeah, this is a bit confusing, so we need a reference point not to loose it...
I can never get out of my own perspective, so in this case it is possible that the whole world only exists in my experience, including you all. But then, talking about this with people who exist only in my perspective make this quite funny...
But I know this above idea doesn't help me much so I try not to focus on that.

I've had a few experiences where I saw stuff and then later they were not there and now I started also watching people's reactions because I've started questioning if I am actually sharing the same reality with them or not, i.e. I might be having different experiences than them. But this just makes me paranoid...