Hi Kelli! I'm not that experienced with water fasting, so maybe others will have some more advice for you...about someone dieing in 3 days while water fasting...I don't know, but it surprises me. Three days is a very short fast...I think I recall Joel Fuhrman (Fasting and Eating for Health), saying that almost anyone is safe to fast for 3 days.
Just listen to your body for what you want to do with the fast. If it's frightening to you, then you can stop, there's no hurry, you can always do it again soon. It's very hard to know what to do sometimes...but you'll be okay whichever you decide, and the fasting you're doing is helping your body. Congratulations!