Hello, Tabanee, Thanks for visiting this site.
Formation gastric juice in your stomach in excess amount. 
Gastric juice i.e. 
gastritis ( hyper acidity) . In this type of situation these is burning sensation in stomach as you have said. 
Reasons are many but few are as , excessive food, fried spiced food, 
anxiety, 
stress, spirit( alcohol), antibiotics etc. 
If gastritis is there  patient feels loss of appetite , burning sensation. 
Most commonly prescribed drug for this is antacids . 
Now a days many medicines are available for this disease , one of them is 
rebamipide but this drug should be taken under the supervision of a doctor.
Good luck , I hope  you will recover within short period. 
Dr. HET