Switch from dairy to almond "milk" or rice "milk". both taste really good, and with some cheerios, the difference won't be noticed. Go to walmart and buy some ground flaxseed and flaxseed oil. Take the recommended serving each day of flaxseed oil and add ground flaxseed to cereal, salad, soup, etc. Go to a health food store and get extra-virgin coconut oil and take two tablespoons each day. You may also cook with it instead and apply it to the skin for a natural, chemical-free moisturizer and sunscreen. Eat recommended servings of fruits and veggies each day, preferably organic (since pesticides promote Candida). get a water filter (I like brita) and drink ten 8oz. glasses a day. Take a probiotic and take enzymes. Both help with acne. try products with tea tree oil for the skin, and avoid cheap "acne treatments".
300g of sugar = 10.7 ounces of sugar (28g = 1oz.). This is an insane amount of sugar. if you must have sugar for tea or coffee, use raw honey or turbinado sugar, in small amounts. The health food stores have low-sugar snacks you can eat instead of the high-sugar ones.
Also, you say you eat "loaRAB of cheerios". you may have a minor reaction to the wheat. Wheat acidifys the body, and promotes Candida.