I have chest pains related to stress and anxiety. If I am worried about something(like chest pains for instance

) The discomfort can be acute but when I am on meds it isn't, and often just being distracted will cause the pain to disappear.
Where is the actual chest pain though? Is it the heart muscle literally tightening up creating Angina type tempory flow restriction? Or does the stiffness come from near or around the heart somehow and just feel heart related because of where it is? I can't think of any other organ in that spot and GI issues, for those of us who have had them, are in an identifiably different location.
If anxiety pain is in the heart would Nitro cause a release of the pain there, at least temporarily? I am curious because of the amount of Nitro Angina sufferers safely use. Anyone?