I think I'm becoming anarex

I've recently started thinking I'm fat. It doesn't make much sense because people generally call me skinny, but I feel fat.

At first I started skipping breakfast. Then I started counting calories. It got to the point where I was upset if I ate over 600 calories a day. In this period I only lost about 4 pounds it wasn't long. I've realized that it's unhealthy though and need to stop. I got rid of my calorie counter, but I still constantly think about it. There's a voice in my head telling me I'm fat. I find myself not wanting to eat. I don't think I have anorexia yet. But I'm afraid I'm developing it and I don't want to. I just can't seem to make myself want to eat.