Tell me about depersonalization disorder

I'm not going to say I have it, for I don't know much about it yet (hence the thread) but I felt I need to educate myself about it...

From time to time, way more often than previously, I find the symptoms of the disorder coming about. Experiences include peripheral vision completely overcome with hallucinations, as well as extreme distortion in the focal vision, and with a moment of staring into one place of anything, it will appear that the object becomes a TV screen, and I essentially feel myself entering the TV screen of the object. My body itself at these times are gone, it seems. I can only feel my head against my brain. Every part of my body seems to be either extremely numb or gone, with perhaps a bit of pressure along one part of the tissue or something in a grid-like pattern.

This doesn't happen all the time, though. When it does happen is when I allow it to- upon listening to music I like, it begins. If I relax myself while doing so, it gradually intensifies. There must be music for it to happen. I know synesthesia has some of the qualities of this, but can it really be this intense? And does it really involve the out-of-body experiences like this?

Another thing is that I have a strong ability to view my mind from the third person perspective, and watch patterns/movements of my mind as it processes things. That really confuses me though, because I do not know from where I am viewing my mind from.

Another thing, I don't know if it has to do with anything, is that I can "listen" to music with nothing actually playing and be completely convinced music is indeed playing when I sort of don't focus on it. When I focus on it I realize it's not music and it fades out, but nevertheless it seems very vivid. I can also induce conversations with "myself" (other people, but involving myself) in my head that sound real, but I KNOW I'm making them so I know they are indeed not real.

But yes, most of all this is about the experience of seeing these hallucinations. I think I can indeed see some of the symptoms (mainly in the peripheral vision) without music as an influence some of the time.

And depression intensifies the experience. If I'm depressed, it gets worse as the consumption of the visuals begins but soon it disperses and seems to add to it like some sort of new flavour. It's very... spiritual(?) overall.

So yes, if you could, I would like to know more about depersonalization disorder. Feel free to ask more specifically about my experiences.