Hi thanks for asking question.
Here are few possibility in your case.
1. First you have these type breathlessness before few months also.So you might have
allergic reaction like asthma to allergens like excess dust, food , pollen etc.Wear mask while driving.chest x ray and
spirometry along with complete blood exination helpful.If wheezing heard on auscultation then nebulization by budesonide and
salbutamol can be taken.
Then regular metered dose inhalation by foracort 200 may needed.
2.Second you might have simple musculosketal pain by heavy weight lifting, improper sleep posture or straining by any activity.simple analgesic with hot compress helpful.
3.If fever associated and cough present
pneumonitis or bronchitis has to be ruled out by chest x ray and CBC.
4.You might have simple viral infection that can lead pain as constitutional symptoms.
Treat it symptomatically.
5.If known case of
hypertension and risk factors for cardiac disease high then electrocardiogram done to rule out cardiac condition.
I hope my suggestion will be helpful to you.
Dr.parth