Hacked Mean Facebook Messages?

[Boss]

I was randomly going through my facebook inbox today and I noticed a message from "facebook user" I can't click on it, it's not a link to another page. But what is weird is that I responded to it (this message was 2 years ago) Obviously that's enough time to forget I responded but I really don't think I did because I didn't respond in a way a normally would, I was mean. I think someone hacked into my account and messaged back. Then 4 years ago "I" messaged one of my good highschool friends who since has deleted me and It was a message asking for a three way with my now ex boyfriend and they called this person by the nickname only I called her. I would never have written that out and I certainly wasn't drunk as I didn't drink 4 years ago. I'm certain I was hacked and I'm very angry about it but it happened so long ago, I think it was one of my friends who knew me (possibly my ex) I'd delete my facebook but for right now it is necessary I keep it. How did I go so long without realizing I was hacked, I keep my profile very private, never make statuses, update my password, don't accept friend requests from people I don't know, profile is set to private, etc.... I'm just worried it will happened again, the two weird messages were spaced two years apart. What was going on? Has anyone else ever had this happen to them with the "facebook user" message and having someone hack you and messaging people back for you?

[pri✍]

"Facebook user" is currently used by FB, that I know of, is indicated that the person's account of the sender is currently deactivated.

Usually, it still show the name, but no prof-pic and the name is in black, same as people you block or block you (which is still the same).

So don't you worry. Especially it's a long time ago and nothing happened, right.

If it can console you, change your password to FB and password for the email you use for FB; don't make both the same password though.