How do I get rid of the agoraphobia symptoms of my anxiety disorder?

Professional help. Agoraphobia symptoms may respond to psychotherapy or medication, or a combination of both. It depends on many factors and is best resolved through your relationship with a psychiatrist and/or psychotherapist.
Face fear head on. You must decide what you avoid the most, and then make yourself do the thing you avoid. Then, try not respond, don't leave, etc. You may do it gradually or all at once. This is called desensitization. Exposure and response prevention are the hallmarks of cognitive behaioral therapy.