Do I have Depersonalization? What are the symptoms?

First off I:

Feel like I don't really know who I am, or when I look in the mirror that person isn't actually me.

I don't know if I am depressed or not, but I feel like it sometimes.

I read something about depersonalization being connected with epilepsy, which I have, and had a seizure when I was 8.

I read you feel disconnected from the world, but I don't know if that's how i feel but I do feel very unimportant to other people. I might just be used to the feeling of being detached from myself cuz I might have had it for a while.

Other signs? Or do I definetly have it?