You seem to be allergic to one of the ingredients in your drinks. I feel sugar is not the culprit, but some other ingredient, maybe malt or some of the additives used. So try some other drinks and see how your body reacts. Also remember that alcohol can also increase the likelihood of developing allergy
to other foods, so you need to note what you eat with your drinks. Over time, you'll be able to identify the offending agent and be able to avoid it.
Hope this has been of help. Best wishes.