while in edit mode and trying to seperate an object by hitting the 'p' key, the whole scene goes blank and there is no access, no ctrl+z to undo it. Usually need to close blender and start over, but of course this has taught me to save, save, save.
Any suggestions

It sounds like you are in Object Mode where PKey runs the game engine. In Edit Mode PKey pops up the Separate menu.

well Im not in game mode, but in edit mode. when attempting to seperate an object I guess like unparenting with the p key - yikes everything disappears. it's a drag.

mtu1492 wrote:

while in edit mode and trying to seperate an object by hitting the 'p' key, the whole scene goes blank and there is no access, no ctrl+z to undo it. Usually need to close blender and start over, but of course this has taught me to save, save, save. Any suggestions

You can press Escape to leave this P freeze frame mode.