I have absolutely NO idea what I did, but I've somehow gotten rid of a bunch of stuff. I was on the Chaotic Uninformity PVP server when suddenly, my + pointer and health bar disappeared. I can't see the chat either. However, when I press ESC, I can see it. Please help, this is making PVP very hard to play.
EDIT: I'm such an idiot. Right after I posted this, I found out I had pressed the F1 key. n00b I am. Somehow I knew I'd made some incredibly stupid and easy to fix mistake.