Xbox 360 Error code 8007007A

Hello,

I've been trying to log into my account on 360 all day and kept getting this error code.

Plus, my original 360 profile picture I had since 2010 is gone (on Xbox 360 only - it does show up on Xbox One and BC) and when I do happen to momentarily log in and start a game, a strange "this game was played on a different console..." message pops up

(I never use BC, so this message has nothing to do with it).

I tryed every single thing I could from the support page and what not, still it doesn't work.

Is my profile corrupted? Have I been hacked or something? I doubt it, since I'm pretty serious about my privacy.

I already had issues with the 8007007A code in the past, but a simple delete/download of my profile solved it, but this time it looks more suspicious and in-depth.

Any help is appreciated.

:)