I have this feeling that you haven't actually validated your email in the beginning. Please accept my apology if I am utterly wrong, but I'm still trying to piece together what you've done and what you're experiencing :} When you first create an account, an email is sent to you with a validation link. Did you click on it to create a password for the first time?
Do you remember that password well?
Are you sure that you were not making typos when entering the information into the client's login screen? We've had people who were trying to log in time after time before realizing that they
were indeed making mistakes. Also check that there are no characters hiding in the input boxes when you are typing - clear them out completely, and then try clearing them out just in case.
There is no way to change your password beside the page I linked to, but we never send emails to the address you register for your account, so if you want to recreate one using another address, you're free to. Check out free temporary email address services like
MyTrashEmail or
MailExpire if you don't have one of your own to spare.