Thanks for your question on Healthcare Magic.
I can understand your concern.
Since your stress echo is normal, no need to worry for heart diseases for your symptoms.
Since you had history of drugs addiction, we should definitely rule out stress and
anxiety in your case because stress can cause similar kind of symptoms like
chest tightness, breathlessness, giddiness,
syncope etc.
So better to
consult psychiatrist and get done
counselling sessions.
Try to identify stressor in your life and start working on it's solution.
You may need anxiolytic drugs too.
Don't worry, you will be alright with counselling and anxiolytic drugs.
Avoid stress and tension, be relax and calm.
Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks .