I don't know when it started but it almost doesn't feel like I'm human. I mean that in the way of for me it doesn't feel like I'm here. It feels like I'm watching everything I'm doing but through first person on a TV screen. Kind of like an NPC sometimes. Maybe it's just numbness or maybe this is how I always felt and every else does but I never noticed?
I get this all the time, I have since I was a kid.
It's called dissociation, it's usually a response to stress or trauma.
Nowadays I only really get it when I have panic attacks, which only makes them worse lol.
What usually helps, if you would like to get rid of the feeling is doing something that will ground you. This means doing something that you feel intensely causing you to snap back to reality.
For me, I tend to put ice on my wrists, take a swig of a spirits, suck on a lemon, run around like a maniac, take a cold shower - basically anything that can shock your senses back into reality.