Can change in food habit affect my anxiety disorder?

No. While it is true that some foods have a lot of anxiety-causing products, like caffeine, if you suffer from an anxiety disorder, it is not from food. In reality, very few people suffer from hypoglycemia, or low blood sugar. If you do, then frequent snacks can help. But you have to keep a close eye on your blood sugar because low blood sugar can be a warning that you will get diabetes later.
Yes. Anxiety can be caused from the release of adrenaline secondary to hypoglycemia. When sugar and artificial sweeteners are removed and small protein snacks are eaten every 2 hours and only protein is eaten at breakfast, many cases of anxiety resolve.