Hi I have Successfully logged in I just forgot that I can log in using my ID

Hi I have successfully answered the form.

Hi I don't remember the time I last logged in with my account because I only tried to login now but it failed, And I also don't remember my USER ID. But I have Topped up. My name on the game is Goodmatthew02

Update/Edit : I have found my User ID.

Whenever i try to login to my account Goodmatthew02 it says invalid name but if i try to create a account with the name Goodmatthew02 it says it already exists can yiu please help me? Thanks