Break your 3 meals into 6-7 (hope you understand)
Aviod - Oil, Sugar, Chocolate, Cheese, Full fat milk and related products, Fried food and specially fast food.

Anyway it's better to meet a dieteeciann and get advices. He will give you a diet plan and will monitor the progree and adjust it time to time.

I know it will not be easy to follow a tight diet plan. when you start and when you see the progress you will love to follow that. when you reduce your 1st 10kgs you can have normal food occasionally (weekends, parties, etc)

good luck