Thanks for your question on Health Care Magic.
I can understand your situation and problem.
By your history and description, possibility of
musculoskeletal pain is more.
But better to first rule out pleurisy (inflammation of pleura) as this can also cause stabbing
chest pain on coughing and sneezing.
Pleurisy can be due to pneumonia,
pleural effusion,
tuberculosis etc. So get done chest x ray. If chest x ray is normal than no need to worry for pleurisy.
You are having musculoskeletal pain only.
So avoid movements causing pain.
Avoid bad postures in sleep.
Avoid heavyweight lifting and strenuous exercise.
Start painkiller and
muscle relaxant drugs.
Apply warm water pad on affected site.
Don't worry, you will be alright in 1-2 weeks.
Hope I have solved your query.
Wish you good health. Thanks.