Macroburst

I've been working on a single player survival world on Hexxit for a couple months now and I've never had any issues loading my world. Today when I tried to open my world, I just get the "Loading World Building Terrain" loading screen and nothing ever loads past that. I tried loading one of my other worlds and it worked just fine. It's only on this one world that I'm having the loading problems. I'm wondering if there's a way to fix it without losing my progress on the world. Any help would be greatly appreciated