Minecraft loads normally.  I am able to play on my Desert world and my Villager world. My main world, with the most builds on is is my Sunflower world.  When I try to enter my Sunflower world, the screen goes black, then two buttons appear on the black screen:  "leave bed" and "open chat."  Then a dim version of the opening of the Sunflower world appears for a flash, then Minecraft shuts down entirely.  This doesn't happen when I go to other worlds, just my sunflower world.  My online name is OakMarker466473. 

It doesn't seem to matter if I try to hit either "leave bed" or "open chat."  Minecraft shuts down within  10 seconds from attempting to play Sunflower world.  I can copy Sunflower world, but can't play the copy either.  

I've restarted my computer, and opened and closed Minecraft.  The other worlds do not seem to be effected. 

Please help.