Synced iPhone 4S and songs that weren't in my playlist were added, as well as 4 GB of other. Also, I updated iTunes and my phone will not sync either.

When I went to sync my iPhone 4s on iTunes a message came up telling me that I would need to make more space to sync it. I deleted some playlists off my phone from iTunes, as well as some apps and pictures from my phone. Once I reached 3.30 free GB, my phone finally synced. I noticed at the top in iTunes it said it was adding about 423 songs and they were all from the one playlist that I left on my phone, which has 444 songs. I went to the iPhone tab when the sync ended and I noticed that the "other" section went from about 4 GB to about 7 GB, leaving only about 300 MB left on my phone. Then, I checked my phone and realized that some songs from previous playlists on my phone that I had deleted earlier were also on there, but were not in any playlists. I'm not sure if that was because I deleted the playlists from iTunes when my phone wouldn't sync and not from the actual phone? I also checked the "on my iphone" tab and it said that there were only 444 songs on my phone, but my phone showed 520 in the songs tab in music. After that, I realized that I hadn't updated my iTunes to the latest version, so I updated it thinking that was the problem. Now my phone won't even show up in iTunes and I have little space on my phone. Does anyone know how to fix these problems? If it helps I use iTunes for windows and I'm worried that if I re-install, I will lose my songs, which has happened twice before.