Hello,
Unfortunately, if you cannot remember your account information and account details, there is not really much of anything anyone can do to help you. That sort of thing is ultimately your responsibility to keep track of. There's no way for anyone else to have access to your account. That would be a security risk.
The best I can suggest is for you to pull up the server list and browse through the names of all the servers and see if you recognize the name of your old server. If you remember what region you were on, that would help you narrow it down quite a bit.

Good luck!