Please help, i think i have some kind of "stuck hack" on my Outlook account

Let me explain:

Since past February, i started noticing a pattern while checking my e-mails.

Everty time i receive an e-mail, it instantly "Re-sends" itself, i have the Re-sent icon on it by the second i receive the e-mail. As if... some hacker has installed some kind of back door or hack or something that has my account hacked or so, so everytime i receive an e-mail, it instantly re-sends it to another one.

How do i know this? Simple.

On my junk mail, i received nuymerous e-mails from Outlook itself that tell me that it's unable to re-send a mail because the destination's e-mail inbox is full, and i now have that e-mail and such, took a screenshot so i can see what i can do.

But i dunno how to operate any further, i dunno how to block that e-mail so it won't automatically re-send to it anymore, and it wouldn't solve the main problem, either!

In other words, my account is hacked and SOMEBODY uses it, and i already have my 2-step verification from my phone and deleted every device using this account except my phone and my computer, to no avail, my mail is either still being used by someone... or it's hacked.

Does someone know what should i do?

Thanks