u/LostRegular2048

I NEED HELP.
A few weeks ago I found sent messages from my account to a friend of mine, I never wrote these offensive messages and so I decided to change my password and enable 2FA instead of just Passkey, after about 2 weeks from the PlayStation app I get the notification saying “have you tried to log in to your account from a device?”, I denied access and now this message trying to log in to my account has arrived again, apparently someone always manages to get my credentials regardless of whether I change them or not, it's only 2FA that's protecting me now, I also forced an exit from all the devices so I had to manually log in my PS5 and Playstation App but still that scary “have you tried ti log in to your account from a device?” Still pops up almost every 2 days, what's going on PlayStation????

(i’m Italian sorry for my awful english)

I just hop in on a random afternoon to play some games with my friend and he asked me why I was so mean in a Playstation message, I asked him what he was on about and he told me that I sent him a message with “I hate you to death, you’re disgusting” at around 2pm, I was outside at that time and no one has access to my account or console.
I can cleary see in the Playstation message section this weird and scary message but I’ve never sent him that text, what is going on?…
I already changed my credentials and forced an exit from all the devices with my PSN account on, am I safe at this point or is it something worse?
My 2FA is already on now since I was only use passkey (Face ID) to access to my account.