Everytime i have sugar it makes my throat swell and i get really tired. i get headaches and it kills my immune system. been months. why?

Not enough info: I have no explanation for the swelling of your throat after "sugar". There are many reasons you could be tired. You would require diagnostic tests to determine the cause. Also, I don't know what you mean by "it kills my immune system." Since this has been going on for months, it's not likely to go away spontaneously. You need to see a doctor.