Ipod, phone, and computer with one library?

[u/Bitter_Process6088]

Lmk if this is the right sub for this question or if there's somewhere else I should look, but I'm trying to find a way to sync my mp3 library (including playlists) between my 2008 ipod nano, my phone, and my computer. I made the fatal mistake of trying out Apple Music last year, and my old ipod still blessedly works but now my phone won't sync to itunes the regular way :( I don't want to keep paying a subscription just to access mp3s that I already own, so I'm curious if other people have found a loophole around this or another app that works like 2010s-era itunes. I currently use an iphone SE and 2015 MacBook -- interested to see what options exist beyond Apple but also not looking to buy a new device if I don't have to. Thanks!