Cant login meta, but I am logged in with Horizon

Hi all, 

So I have the Quest Meta 3 for 2 years now. When I bought it I did set up a gmail account so that one was solely for the Quest 3. I lost access to my account and I can not recover it. It was made on an old phone (logged in on it) but even the phone tells me to verify again it is mine to keep my account safe (..). Anyway, long story short: I can not recover it, even on the phone, because there is no information or anything.

On this telephone I am logged in Meta Horizon with that email too.  The same account as on my Quest 3. Now, if I wanna change my email I need to go into my account. 
If I wanna recover or change anything, the only thing Meta is able to do is to send a recovery password to my email - which I can not enter.
I am logged in on my Quest 3. I have proof of payments (in the store) with my CC I still use today. 

Is there ANY way that Meta can help me with changing my email? 
I have multiple bought games and I am afraid that when there is an update or anything or in case it might happen I need to login again, I lose all access to my games.

Thanks for the long read and I really hope there is a solution!

Negan.2025