Very LAGGY

Today when I was playing Minecraft I experienced some lag and issues with placeing and breaking blocks. When I went to place a lantern, (featured in the new update) it glitched and gave me a whole other stack of lanterns. I freaked out and reloaded my game, only to see another stack of lanterns. Then when I went to another server of mine, I decided to build a house. I messed up so I tried deleting it but it said was as if there was nothing there. I broke grass instead of the wood I placed. Please fix this!