Anxiety
Anxiety is one of the most common of mental health problems, affecting many Americans at any given moment. Luckily it is also one of the most treatable of disorders.
There are a variety of types of anixiety: ranging from the generalized sense of worry that you feel much of the time to fears/phobias about specific things (including social contacts).
Here are several websites that may provide some useful information about what you feel and/or ways to deal with your anxiety.