AF Point Problems

About half-way through an event yesterday I started having problems with the focus on my camera. The only point that will light up is the one on the far left. No matter what I try to focus on, my camera will only focus on what that point is on top of. This is making it very difficult to shoot pictures. I don't know if I accidentally switched something in my settings and seeing as it's a weekend, I can't call customer support for help and I need to shoot some more pictures for a project today. If anyone has any advice or has had this problem and knows what to do I would greatly appreciate any help. I made sure there was no dust on either side of my lens, the filter, or in the body several times.

Hello. Are you using single point focus? AF-C mode? Looking through the view finder, you should be able to move your single focus point around. Make sure at the back of the camera, the cursor switch is not locked or in the "L" position.

Sounds like you are in single point focus mode
You can adjust this back to center using the the adjustment ring