How to get the music on my iPhone onto a new ITunes library?

I got a new computer and didn't realize it wa this difficult to get the music on my phone onto my new iTunes library.

You should just be able to sync it to your new iTunes. If you can't, use the AutoPlay feature on your Windows computer, go to "Open Folders to View Files", go to your music, and copy+paste your songs into your iTunes account. Best answer me if I helped in any way!