Hi It seems you are having a panic attack. It can be isolated or a part of a panic disorder. This is an anxiety disorder. This can be sometimes involved with other mental conditions. It can be best if you are evaluated fully. There are medications which help you overcome this. Psychotherapy and counselling also helps in mild to moderate severity cases. Please consult a psychiatrist or direct consult me. Take care

Tremors, feeling anxious or nervous, sense of panic, sweating, increased heartbeat, feeling of impending doom, stomach discomfort, dizziness etc are signs of anxiety. These can be debilitating. If the anxiety is overwhelming, consult a Psychiatrist at the earliest. With the right medication and counseling, it is likely your symptoms will improve.

The fear with out reasons are called phobias and there is associated anxiety with such fears. You need to identify what type of fears you are currently having. The difficulty in breathing is due to anxiety.