Frames per second at -1 in some areas of my game

I don't know everything everyone else is dealing with but for me there are two issues, 1) in my village both villagers and my iron golem have disappeared at times, and 2) since the new update I am having trouble with frames per second in my best minecraft world, (sometimes less than I frame per second, which isn't good when zombies are around!) but only in some areas so far... sadly, all of them are in my stronghold and close surroundings. This has made the game unplayable suddenly. I don't quite know how to figure out how to fix this. If you could refer me to someone who can help, please email me at elvensong2000@yahoo.com. I really miss my best minecraft world. I wasn't sure how to find my 'affects Version' listing so I took my best guess at it. Sorry about that.