Hi Dear,
Welcome to HCM.
Understanding your concern. As per your query you have 
shortness of breath and dizziness. Well there can be many reasons for symptoms you mention in query like 
ear infection , condition like meniere's disease , food poisoning , heart problem or anxiety disorder . I can also occur due to viral infection , 
chest infection or cardiac problem. I would suggest you to stay calm , avoid bending forward , avoid food like nuts and sea food , drink plenty of fluid and drink green tea thrice a day . If condition doesn't get better then 
consult ENT specialist for proper examination . Doctor may order certain test like CT scan of ear , examine with otoscope , rotatory chair test and balance test . Doctor may prescribe antibiotics like 
gentamycin , antiemetic drug ,anti inflammatory along with vestibular therapy . Doctor may also refer you to cardiologist ( as your already been to cardiologist ) or to chest specialist for chest infection .
Hope your concern has been resolved.
Get Well Soon.
Best Wishes,
Dr. Harry Maheshwari