Can someone hack me in a private message on Facebook?

. Last night I received a message saying that my friend had changed her name on the message we had been chatting on earlier. She uses Messenger. I don't. The name was changed to some random letters and it also said she had added the nickname "G" on the message. I asked her why and she said she didn't do it. Then a voice message popped up with a song on it and it appeared to have come from me but I didn't send it. I can't even send voice messages. This morning I couldn't get online so I tried to shut the computer down. When I did, Windows started doing repairs and asked if I wanted to restore to an earlier date so I did. then it shut down and I restarted it. Firefox then started up. I had to uninstall and reinstall google to make it work.