Thanks for your question on Health Care Magic.
I can understand your situation and problem.
Itchiness inside of chest can be due to
bronchitis.
Since you are smoker and having bleach exposure at work, possibility of bronchitis is more in your case.
So get done PFT (Pulmonary Function Test).
PFT is needed for the diagnosis of bronchitis.
If it is normal than no need to worry much.
You should avoid
smoking as soon as because cigarette smoke can cause itchiness in lungs.
Also wear mask at work place to avoid bleach fumes inhalation.
If stop smoking and wear mask at work place than you will mostly improve and you will not need alprazolam.
Hope I have solved your query.
Wish you good health. Thanks.