Burning sensation when urinating is an inflammation.
Plus all the other symptoms you have mentioned are very similar to candida (you'd need to further address them to make sure). And YES candida is fed by Sugar and drinking soda would cause these symptoms. Actually the first step of the candida treatment is to go on the candida diet= no sweet (not even fruit is some cases) no carbohydrates (grain) but buckwheat, millet, quinoa, brown rice.
Scars! In result of acne? IF so it could also be due to candida.