Thanks for writing your query.
After reading your query, it seems that you might have suffered from soft tissue injury
You can take anti inflammatory like Ibuprofen
twice a day after meals along with an antacid
Other possibility can be an insect bite for which you can add an antihistamine like Fexofenadine
120 mg along with the above medications.
You should get yourself first clinically examined before starting any medication.
I hope this is helpful to you.