Hi and welcome back
There is a way to get your account back, just contact Arenanet support. They will ask you lots of info to verify that the account was yours including character names (if you remember any), professions, CD keys (should be inside your boxed versions), etc.
The email is what most people forget (or stopped using it 15 years ago and is deactivated) so I am sure you will get back in game pretty quickly. Good luck!