House collapses

Sorry, you can't get it back. Sand and gravel are affected by gravity now, so sand and gravel structures will collapse without support.

I worked 30 min on this and I founded a way to fix your house but you will need
tons of signs do you know signs can be placed on signs just create a roof with wall
signs and rebuild your sand roof on top of your sign roof also don't make holes in your house so just put glass in your windows

That's actually a pretty cool idea. However, you should probably wait for 0.6.1, or the save bug and gravity bugs will keep undoing you work and making you lose materials.