If you are in intense pain, it will be best to get an Xray done to check that none of the ribs are fractured or cracked. A cracked rib will cause more or less the same symptoms as a pulled chest muscle.
Meanwhile, at home, the best method of treating a torn or pulled muscle is by strapping the chest so that the movement of the chest wall is minimised to some extent. The strapping will have to be just tight enough to prevent any bending or twisting movement of the chest wall but not tight enough to cause difficulty in breathing.
I am afraid that you will need to take a painkiller like Motrin 500 mg twice daily. Take the pill immediately after a meal on a full stomach so that it does not cause any gastritis. It is the increased acidity in gastritis that causes the nausea. You can take an antacid like Mylanta 30 minutes after taking the Motrin or you can ask the doctor for a prescription for an acid reducing medicine like Protonix.
If it is only a pulled muscle, you will feel better with a hot pack or a hot water bottle applied to the place. You can also apply muscle relaxants like Tobricin ointment (OTC) or Icy-hot over the area.
But, it would be best to get an Xray done before you start any home treatment.
I hope this helps.
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