Is there something wrong with my digestion?

So over the past week I've dropped almost 10 pounds. It happened really fast, and I run 6 miles at least twice a day. I really love how I look and feel and it makes me even more motivated to continue losing the fat. The only problem is, I can barely eat anymore. Every time I look at food or think of it, I feel I'm going to throw up. My stomach goes into a stage where it feels like it's bubbling and churning. I haven't eaten a thing since Friday and I'm really worried. I just can't eat without feeling horribly nauseous and sick.