Ps3 won't let me sign into my account.

Okay, so the other day I decided to play FIFA 13 on my PS3. I hadn't played it for awhile so the next day I came back to play again and it said the data or whatever was corrupted. So I looked online and it said to put it in safe mode, then restore the database and settings, so I did. That fixed that problem but after that I tried to play a game and it said something about the trophies or whatever. So I looked and I wasn't signed in so tried to sign in and it wouldn't even let me connect to the Internet. So I looked on the Internet browser(where it was working) and it sent like a message to log onto my wifi carrier(AT&T) and I tried to do that but it wouldn't go through. I'm not sure if it was because the Internet wasn't working or what. Should I do it on my computer or something? I don't know what to do anymore and I really don't want to get rid of it.