Panic attacks - feeling like I'm already dead

Okay, so I'm struggling to find a place to express what I am going through. Hopefully someone can relate or share some thoughts on what I'm experiencing.

For many years I have experienced dissociation. I have felt like I've been walking through a continuous dream or watching a movie, that is my life.

Over the last year this feeling has been progressively getting worse and now I am experiencing panic attacks that are randomly triggered by someone either saying something about not being alive, being plugged into a headset, and random deep thoughts of being in a coma???

I think what has triggered this might have something to do with the small number of times I tried marijuana. I have had major freak outs, the three times I tried it. I went into some sort of psychosis where I thought I was in an ambulance and resuscitating myself by hitting my chest and screaming but I can't remember it, and it's honestly hard to write it out correctly.

But prior to trying that, as a young child I used to have really strange experiences of what I used to call "dreamy landing".

Basically, "dreamy landing" was how I explained what I was doing/feeling when I'd try going to sleep. I used to have night terrors alongside this but I would lay in bed and shrink, then fly around the roof of my room... I don't know if I had a really vivid imagination or if what I was experiencing was real... I also used to grow super big, a bit like Alice in Wonderland but I could fly around.

Anyway, now I'm just watching TV having internal panic attacks and falling back into this scary delusion that I'm dead or in a coma or just tripping out and not remembering what's happening.