Hi...if your symptoms are brought about by physical activity and relieved by rest it fits into angina definition.
Since you have rightly got everything evaluated, even coronary angiogram, luckily you don't have major epicardial coronary artery blockages. Unlikely you have any major problem of heart.
However you are not wrong in suspecting microvascular angina....which can be as disturbing as usual angina and arteries are normal
Next Steps
However I would suggest meet a neurologist or spine surgeon and rule out any nerve related issues.
Get your serum
Vitamin B12, Serum
Vitamin D and ESR checked.
You could also meet a Rheumatologist if no other cause is found.
Microvascular angina, if very strongly suspected is sometimes picked up on Stress Myocardial perfusion imaging (which is a nuclear scan)- but at present not warranted unless other causes ruled out and symptoms persist.