It could be an abscess l!
There is no relation of food as such but there is some disease activity in your body.
In this stage take only veritable diet avoid non veg l, do not touch or press it. By taking that medication it will resolve in 7-10 days.
Next Steps
if It do not subside consult a surgeon he will remove the abscess and that will heal.
Health Tips
for proper response try to upload the pic of your galti
GET WELL SOON