1)try to find out what triggers the acidity, it might be dairy products or peanuts or anything else. So keep a record of your diet in relation to episodes of acidity and avoid the cause.
2) Take 1and a half teaspoonful of Avipattikar churna by mixing it with warm water at night for next 5-6 days.
3) take Bhunimbadi kadha -a liquid medicine -2 teaspoonfuls+ 2tsf water after both meals for the next 2 months.
4) eat small portions of food at regular intervals. Do not overeat and do not go hungry. Have a proper breakfast everyday.
Next Steps
if you still face problems then consult a doctor. you might need detailed advice concerning diet.