What Causes A Sudden Increase In Weight Without Any Diet Change?

I m a 22 years girl My weight was 42 kg suddenly became 52 I think the reason I started work somewhat tired.. I work at the airport now and my hours of sleeping are not fixed as well as I had.. since I was a kid I do not love sweets and I don t feel that i want sweets .. but know i feel all time that i want sweets and i eat it too much.. what is the solution? ..