You need to lose 3 KGS only but as you said u have more tummy fat that need to be lose. I can help with tummy fat loss without gym with healthy diet and exercise only.

Hello, gaining weight suddenly can be because derange hormones like Thyroid hormones. So kindly just check once. Till then you start up with low calorie diet. In which focus more on fruit and salads. Avoid fried foods, bakery foods, processed foods. Avoid cream, butter, ghee. Eat more of complex carbs like whole grain, oats, Daliya. Start your meal with salad. Regarding exercise you can start with 30 -45 mins walking daily. Also include plank or crunches for stomach. You can also massege in personal for detail diet chart