I dont know your age but considering you in mid age group---
You should avoid Vit. c if you have tonsillitis as vit. c tablets cause mouth ulcers on long use.
Secondly you must see that you have reflux or acidity in stomach as this is one of the reason of recurrent tonsillitis
which is neglected. and as you said you are taking antibiotic again and again.and get tonsillitis and flu very frequently.
You can take---
Tab. Mucinac 600 once daily
+Domperidom two times a day half an hour before meals
gel 2 tsf two times a day half an hour before meals
Keep head end of bed elevated.
Avoid alcohol, Smoking
Do brisk walking daily
Go for walk after dinner
Avoid spicy food
Avoid late night coffee
follow up after 7 days.