Incorporate more protein and fat in your diet. You want to slow down the digestion of sugars to prevent a spike in blood sugar. Try having a spoonful of peanut butter or handful of nuts to give you fat and protein to slow digestion.
Get moving! Even if you experience a sugar crash and all you want to do is nap, it is best to get moving. Something small like a 15 minute walk can do the trick. This will help your muscles use the blood sugar instead of just storing it.
You may want to ease up on the fruit. Of course fruit is healthy for you, but it still contains sugar. If you overdid it on sugar, try to swap out your fruit for more complex carbohydrates. Instead of fruit and oatmeal for breakfast, have oatmeal with some sliced almonds on top or whole grain GF toast with avocado.
Hydrate, increase your water intake by 16-20oz, this helps the kidneys excrete the excess sugar, helping you and your body feel better. Try adding some lemon slices to your water which can also help.