Here I'll express about both how it feels and perhaps you can relate. (that's my personal experience) 

Derealization

This happens randomly at random time and it stays for multiple days. When i suddenly start to think everything is fake, it's all made up or it feels like am stuck in simulation or a dream and everything seems not real. While texting something feels like it's the body that it texting but am not in my body.

You can feel like you're in the back of your eyes controlling this body or simply not in the body. You function normally from outside, nothing seems wrong except you're not smiling much or being cheerful and someone who cares might ask what happened? Or no one will ask at all.

Depersonalization

Remembering how i look very clearly feels strange, then i look at the mirror to recognize myself, not that i completely forget how i look or i am but i feel like i don't remember my facial details or simply myself.

Sometimes i literally have to go to my own phone gallery to see how i look. Sometimes i don't even check anything, but whenever i show up infront of a mirror i feel strange who is that person? Is that even me? Or something pretending to be me? That's my thoughts at that time.

So in normal days you feel back into your body again functioning totally normall like currently i am. Then both can suddenly appear at any moment.

Let me know about your DRDP. 

How Derealization and depersonalization feels like?