That's the reason why you should carfully consider what to do. Do NOT try to drop your real identity as it is impossible. By trying to do so you destroy more as you gain. Split your identities is the magical way.
Create your online identity and create a border between that and your real identity. Maybe it needs more than one identities which is okay. Another nice term and way is compartmentalize. Try to understand what that means.
Create your threat model. The NSA isn't your worst enemy and you can't win against it. Be realistic and honest to yourself.