@lorit,
Let's use proper terms (makes things a lot less confusing). You are talking about personal accounts, rather than a page you manage where, for example, people who like the Beatles gather, yes?
Easiest way to find your old account (I am assuming it had tight privacy settings) is to go through the friends list of a friend, then add yourself. If you still can't find the old account, try having the friend send a notification to your old account, suggesting it befriend your new account.
Because you (presumably) still have control over the email address you used to create the first account, you should get a notification. Click on that, try to login, and tell it you forgot your password.