This is not really a question that can be answered very well over the internet. You may have more problems than you can handle by yourself. You may have a physycological disorder. You may have a chemical impalance. You may be depressed and be misdiagnosing it as nervousness. You may have a nervous gene. I got mine from my mother. You may be immature and might grow out of it. You may be too sensitive for the real world. And these are just a few of the things that might cause you to be nervous all the time. So you should get a real check up and the the doctor doesn't find anything, a few sessions with a counselor would be really good for you. You might find out that you are not really nervous all the time but actually nervous the normal amount of the time.