Chronic Anxiety. Help and learning.

Over the last four years, I have been feeling academic anxiety in increasing magnitude. Of late (in the last eight months), I have been having periods of intense anxiety more and more frequently to the point where I have begun eschewing social interaction and avoiding/delaying situations (presentations, work reports) that cause the upset. As of now, I have been in a new work environment for two days and I freeze when I am around my new colleagues. I cannot even bring myself to greet them or make small talk, or even make eye contact. I feel overwhelmed and uncomfortable, and I feel like running away from the workplace and never having to go back. This is in spite of the fact that they have been reasonably friendly so far. I leave the work place as early as I can without appearing irresponsible, and dread going back the next day. I am interested in the work and I need all the help I can get from my co-workers but this anxiety I have around them prevents me asking their help and learning.