Shark Bacon
glacialium
I sound like a broken record because this has been my advice three times today, but detox. Sodas contain multiple chemicals besides just caffeine that are both addictive and dehydrating; detoxing will flush a lot of them out of your body. I would suggest green tea; not only does it contain traces of caffeine to help your headaches, but it's incredibly healthy and good for detoxing, so you could drink as much as you wanted. Adding watery fruits (such as watermelon or strawberries) and natural foods rich in protein and fiber (such as beans and quinoa) to your diet are helpful too because both will essentially rid your body of junk while giving you the energy boost you're used to from soda.
I've tried green tea, and it's so bitter
sad I've been drinking a lot of strawberry/pineapple/yogurt smoothies, though, could I mix green tea in there you think?
You could do that. Strawberries, pineapples, and yoghurt are already good for detoxing by themselves though because strawberries have antioxidants, pineapples have bromelain, and live yoghurt has beneficial bacteria, so unless you just wanted the extra caffeine, you could leave the green tea out of it. If you like coffee as a source of caffeine, you can try decaf herbal coffees; they help detox too, and they're usually sweet enough to get rid of cravings for sugary soft drinks.