1.8 Snap Shot Inventory Bug

After downloading the current snapshot 1.8, I started playing and went to my Ender Chest and all my Inventory was gone along with all my inverntory I had on me and my Armour. I shut it down, restarted it and looked again... nothing.
I started to play my Minecraft 1.7.4 world and checked my Ender Chest and nothing as well. But I had items in all my other chests. My on hand inventory was also still gone along with my armour. Then I realized that my sound wasn't working. I shut it down again and restarted it. Still no sound, nothing in my Ender Chest, and now nothing in any of my chests approx. about 30-40 of them. The only one that had anything in it was my coal chest. So now i have no inventory at all. The world I've been playing on for the last 5-6 months collecting inventory. Im sadden thats its all gone. This is the first snapshot I have ever downloaded and it will be my last.