Our DS6 also had pretty big fears that started when he was around 3. They ran the gamut from Swiper (yes, he was scared of the swiping fox in Dora the Explorer) to the sun going supernova. He is still scared of most movies, but has become quite brave in relation to many of his past fears: he can now go for hikes and camping in the forest without being too scared of bears and getting lost, he no longer asks about what possible natural disasters might occur in places we visit, and he can now swim in lakes without fearing what might lurk beneath the surface. He is even actually fearless in many respects, now that I think about it - this summer, he did some awesome cliff jumping off a 12 foot cliff!
I don't have any new advice to add to DianaG's, except that it's also a good idea to be patient. If you spend enough time doing what she suggests, you'll likely find that it will all fade away before you know it. When our DS's fears were at their peak, a few people suggested that it might be because kids often understand risks before they can deal with them emotionally. And this may be even more pronounced for GC, given their level of understanding at such a young age. Plus, they may understand the risk but not understand the likelihood/probability of the risk actually materializing. So discussing these things with him and allowing him time to process them may be the best approach.
I think we're out of the woods with DS at this point, fingers crossed that it doesn't come back! Good luck to you, and hopefully it will also pass sooner than later.
