Thanks for posting your query.
Is there any positive history of allergy
in you or in your family?
Chest congestion after working in garden suggest some sort of allergy and you should consult with physician/ chest physician.
You should go for thorough check up with chest x ray
and allergy test.
You may have soft tissue injury
You should also consult with orthopedic surgeon and should go for x ray of the affected spine part.
You should take pain killers with muscler elaxants for a short period.
Dr. Mayank Bhargava