This is anxiety of social spaces or places also called as agoraphobia. This may start as we tend to focus more on our physical sensation and thoughts of future. Some threatening incidence in past may have triggered these thoughts of social phobia. When we start focusing on or body sensations our thoughts frequency increases and we feel more vulnerable. A psychologist can help you with a treatment plan to step by step reduce this anxiety. With proper support and graded exposure techniques this can be resolved and you can live a healthy life with social interactions.

Anxiety is treatable disorder so kindly consult Mental health professional

Please give me a little more history....When it started, was there any recent  stress etc. It looks like u r suffering from anxiety disorder. U will also need some investigations. See a psychiatrist. U will get well.