I desperately need help

I cant log in to my main account.
Its been a while since i logged into my main account. The phone i used for the authentificator is long gone. (but im still using the same number)
For the Login i need the authentificator.
For the authentificator i need some mysterious serialnumber and a resetcode (i have no idea what that means).
I cant log in anywhere to get support.
To get support with my account i need to login with my account ( very smart design blizzard …)
what am i supposed to do now? is my account gone for good? i just made this throwaway account to get help.
so please, can anyone tell me how to retrieve my account?