Cannot transfer music from iPod touch to my iTunes library

I had TouchCopy recommended to me for that on Apple support communities, worked really well.

There are 3 ways to transfer music from iPod to iTunes:

Mthod 1: Using iTunes. Connect your iPod to computer, then open iTunes and click "File" > "Device" > "Transfer Purchases from Your Device Name". By default, the exported music will be saved at C:Users/Administrator/Music/iTunes/iTunes Media. But this method can only used for purchsed music.

Method 2: Using Dropbox. Upload your music on iPod, then download from your computer via same Dropbox ID. Add downloaded music to iTunes.

Method 3: Using iTransfer. Connect your iPod to Computer. Select source music on "Music" section, then right click to transfer to iTunes.

Here are more detailed steps for these three methods: 3 Ways to Transfer Music from iPod to Computer Windows 10

You could try Leawo iTransfer to solve this problem. Just follow the below steps to do that.

Run Leawo iTransfer

Select Music Files

Transfer Settings

Transferring Music from iPod to iTunes

Many iPod users have asked this.
It won't be a problem if you use AVCWare iPod to iPod/Computer/iTunes Transfer.
It automatically transfers your iPod and iPhone music, video, playlist, photos to computer and iTunes. Backup all your music and video in a couple of clicks. Really makes music and videos sharing pretty simple and enjoyable. Wish this can help and good luck.

I think its step by step guide is most helpful.
http://iphone-to-computer.net/transfer-songs-videos-photos-playlists-from-ipod-to-computer-itunes.html

It is easy to use and you can try it now.

In the official company FAQ, Apple originally stated that:
Synchronization occurs only in one direction, from your computer to your iPod. This means you cannot transfer music, automatically or manually, from your iPod to a computer, and you cannot use iPod to copy a music library from one computer to another.
Synchronization generally occurs only in one direction, from your computer to your iPod. This means you typically cannot transfer music, automatically or manually, from your iPod to a computer, and you cannot use iPod to copy a music library from one computer to another.
An exception to this is the transfer purchases feature which allows you to restore purchased iTunes content to your computer from your iPod. Additionally, if you legally are allowed to copy music or other media files , you can configure your iPod as a storage drive to move media files.
iTunes 7 and higher allow one to use an iPod to transfer songs purchased through iTunes to as many as five authorized computers. This only works for songs purchased through iTunes, not those ripped from CDs or downloaded from other sources, which are much more common.