Has a chest xray been done to rule out any rib fracture, chest infection, or air in the pleural space?
There could be several causes of the symptoms you are having including a muscle pull, injury or trauma at the site, chest infection, etc.
Do you have any associated symptoms?
You should apply some local pain relief medications, take some oral pain relief medications, maintain a proper posture throughout the day, try some warm compresses.
You could take some antireflux antinausea medications and see if they help with your symptoms - this could be pain due to reflux or GERD.
Consult the doctor if the symptoms persist and discuss whether you need to get any investigations including a chest xray and ECG done.
Let us know about how you are doing and if you need any other information.
If you are having sharp pain in your chest you should get it checked out. Seriously, you should go to Urgent care of an ER or something. You do not want to mess with chest pain. It could be nothing, or something serious. There is no way to tell unless you get checked out. Please get some help. Constant coughing or sneezing might make your chest hurt, but sharp pain can indicate other problems too. I had chest pain really bad a few weeks back and found out I had pneumonia. So, it is really worth getting this taken care of. Peace and get better soon