I honestly think it's okay to feel that way sometimes. We ALL have those days. This becomes a problem, when you feel this way ALL the time. That's when you need to do something about it. But until then, if we didn't have those days, we wouldn't appreciate the good ones right? It's kind of nice to know you're alive sometimes. Chin up sweetie. The sun will be shining tomorrow. I promise.
When you feel like that you need to find something that interests you to occupy your mind. Everyone feels like that once in a while but if you think about it constantly it can be depressing. Remember this, you are always "something" to somebody. Ask your family. I'm betting that you are a wonderful person.
Everyone does from time to time. As long as the feeling doesn't hang a round too long, you should be fine. I hope no one in particular made you feel this way. If they did they are a fool. Get some rest tonight and I am sure tomorrow will be better.
Just the fact that you feel like nothing means you're feeling something. Something ain't nothing. And yeah, it's ok. When I was young i went through a period when I thought I couldn't think. How oxymoronic is that?