I edit my playlists but they revert next time I open.

I use a Dell laptop running Windows 7 Pro. Iphone5S and IPod 4.2.1 Model MB533LL

I do all editing of playlists on the laptop. Then I sync the IPod with cord. That part is OK. Then next time I open ITunes on laptop, the deleted playlists are back. In addition to that, there will be almost duplicate playlists of many but not all of my playlists. The almost duplicate will be the same name followed by a 1 and it will be the same content but in most cases missing some of the songs. I have no idea how any of this is happening. I had been syncing the IPhone 5S right after syncing the IPod & it seemed the phone was changing the ITunes rather than the ITunes changing the phone. So today, I did not plug in the phone but it started syncing wirelessly anyway. Now everything is messed up again. I am losing tons of time with this mess. Please help! Thank you.