Hello,
Since you have done all cardiac tests which are normal, your symptoms are likely non cardiac. Myocardial MPI being normal doesnt need you to undergo CT angiogram. I think you should stop thinking about it being related to heart.
Cause of your symptoms could be related to acid peptic disease or gerd or muskuloskeletal.
Next Steps
Quit smoking if you are smoking. Consult your physician for further tests.