What you are feeling is very common and you are not alone. Many people suffer with anxiety and do not even realize it. Depersonalization is also rather common with anxiety.
You have come to the right place with many people who can relate to what you are feeling and saying. How are your parents, do they talk to you about it? Also, there are many places that now offer in person support groups. Often times those are SO helpful because you can talk with others who share your feelings.
Do you get to see a therapist regularly?
I do talk to my parents but i dont like to and no i dont go to a therapist regularly i have only ever been to the psychiatrist. I get panic attacks alot and my anxiety is always there. it used to come and go at random times but now it just comes and stays for the hole day, i sometimes fear that im actually in a dream or dead. sometimes i even wake up with it