I have PCOS. What i eat correctly?

I have PCOS. According to my gynac, I'm not suppose to eat anything from outside. I try my level best not to eat anything made outside home. But I work in an IT company, n my schedule keeps changing according to the project requirement. Sometime I don't have time to make food for myself n then I need to eat from somewhere out. Can you please help me getting a right diet, correct amount of calories I should have in a day and at the same time I can reduce my weight also by controlling what I eat correctly? I do little excersices at home for reducing my tummy. My height is less n due to my weight I look more fat then what my weight is. My weight has increased to 64kg in last 3 yrs from 52kg. My blood test have everything normal. But it shows vitamin D3 and B12 is very less. I am a pure vegetarian, so it's difficult for my to take vitamin B12 from vegetables. Please help me in planning a right diet for me. Thank u.