There is a considerable amount of misinformation about sugar, just as there has been in the past about salt, and saturated fat. I recommend reviewing the following articles with an open mind:
http://www.thenutritioncoach.com.au/anti-ageing/defending-fruit-and-other-noncomplex-carbs/
http://www.abioenergeticview.com/2-7
When you go on a low carbohydrate diet what happens is the metabolism slows down and immune function is decreased allowing bacteria, parasites, and fungus to overgrow in the small intestine which is supposed to be sterile. This can cause negative reactions to sugars as our metabolic rate controls the amount of gastric acid, digestive enzymes, as well as body temperature/immunity which are all decreased when carbohydrates are restricted. This results in impaired digestion and the false reinforcement of the idea that sugar is bad for you. Notice how fruitarians who don't restrict carbohydrates can guzzle sugar all day long without any problems.
More concentrated sources of sugar like honey or dates should be easier for you to tolerate in the short term. I recommend consuming as much sugar as you can while taking low dosages of either tetracycline or penicillin which are very safe antibiotics when enough sugar is in your system. The side effects from antibiotics result from increased endotoxins and other byproducts of bacterial death which are detoxified in the liver in the presence of adequate glycogen. I can't recommend you to take antibiotics without a source of tolerable sugar because of potential side effects. Plain sugar dissolved in hot water, well cooked white rice, white potatoes, and refined grains are also pretty easy to digest as these sources are broken down very early on in the digestive tract where bacteria usually have not breached.
What I did to reverse this condition was to consume large amounts of honey, and other sugars initially while taking herbal antimicrobials which are much easier on the system, but don't fully eradicate bacterial overgrowths in my experience. I was able to regain the ability to basically digest any food after taking herbal antimicrobials and eating a high carbohydrate diet, but my metabolism experienced the most dramatic increase after taking low dosages of the above antibiotics. I only experienced the feeling of a very minor cold the first several days of taking these antibiotics, but I was consuming around 3000 calories of daily sugars from orange juice and other foods when I took the antibiotics which I am sure made my body better able to handle the stress.
In conclusion, I don't believe a low carbohydrate diet is compatible with energy, longevity, or health in general and I implore you to recognize what the low carbohydrate diet has done to you, and escape before more damage is done.