It is not uncommon to be nervous around people you do not know, but it is best to consult a doctor to confirm if you have a medical condition. He can consult with you to determine the best treatment for your anxiety.

the feeling of anxiety is caused by a perceived threat by the nervous system, panic attacks are the nervous system going haywire.

The noun form for the adjective nervous is nervousness.

Panic, for one.

Possible anxiety disorder. Speak with your doctor.