The stress test should show sign of blockages, but it is looking for changes from before and after exercise.

If you are athletic, and have been for a long time, you may have extensive collaterals that open up and assist you when exercising, but are shut down the rest of the time.

These tests looked for changes, and for damaged tissue, and calcification. They found none. Only an angiogram could verify if you have blockages or not.

Try not to stress. Very important. Critically.
Don't smoke, drink alcohol, or even see scary or action movies. MELLOW. No arguments.

Start or continue a GRADUAL exercise program, eat an EXTREMELY low fat diet, and eat plenty of high anti-oxidant foods. If there's nothing wrong, you'll live to be 100. If there is something wrong, you'll slow it completely, and the exercise will strengthen your heart, and possibly reveal the angina as from something non-anxiety related.