How to tell if I have anxiety disorder or something?

Get diagnosis. This is a common problem - after ruling out medical conditions there are a number of treatment options. For the basics about anxiety disorder see: http://cpancf.Com/anxietydisordersbasics.Asp.
Agree w Dr. Bordini. A psychiatrist or clinical psychologist should be able to diagnose an anxiety disorder. Anxiety symptoms can include feeling nervous or irritable, muscle tension (especially in neck, shoulders ; back), poor quality or minimal sleep, lack of concentration ; easy fatiguability. Lump in throat or butterfly in stomach sensation can occur.