Extremely Confused

This isn't going to be too long, but around two or three years ago, I underwent a "syscovery," more commonly known as system discovery. I didn't think much of it at the time, but looking back on it, it very much impacted my current life and how I go about things in general.

I already know a lot about myself, and supposedly about "others" as well. Well, I thought I did, but the more I continue to question myself, the more I find that it's becoming extremely more complex and confusing. The oddest experience was when I was laughing with my brother, and somehow he could tell I wasn't being myself because the way he knows my kind of humor was far different from how I was acting at that moment.

I remember this vividly (kind of.) And after he said that, it was like someone slammed on the brakes, I remember feeling extremely lost afterward. Awhile later, after that encounter with my brother, I went back to my bed and sat there for what seemed like a while. That made me realize that the entire time we were talking, I wasn't alone.

That realization also made me realize he'd been there all week; I just couldn't notice or tell at all. And when I say "he," I mean some random kid named Subspace (Tripmine), basically. I didn't know he was there the entire week. Hell, I can hardly tell unless it's very obvious that someone is going to "front." And that's why I feel like I'm faking it, because a lot of the time I just can't tell. When I get up to talk to other people (who aren't online), it's like someone stops the car all over again. I get that same "pull." it's like they keep leaving.

It feels like they go away, and it's happened more than once. I thought I knew everything, like how they all went away after being needed once. I don't think that anymore. I'm really starting to think it's more covert than I ever realized, that maybe I'm not as smart as I thought I was. It's really fucking with me.

I don't know what this is, and i'm really only asking for help to possibly identify what the hell is going on (before I talk to my therapist, i've already got a few theories.) or just some simple comfort, anything really, I just am sooo lost.