Forum account not activated, idk email address

So, I've registered like 3-4-5 years ago first, but I didn't confirm my email address. I then had this account registered and properly activated.

I'd like to use my other account. I can prove that I am the rightful owner of the username because I know the password and I have accounts on the same name in a lot of other games (including MTA, SA-MP, email accounts, paypal, fb, etc.)

I don't really know who I should PM about this so I just posted it here.

If somebody from the staff could PM me to resolve this that'd be awesome, thanks!