Apple Music not syncing iTunes library from PC

I got talked into getting Apple Music having had a beautiful relationship with my iTunes and iPod and now have the worst of all worlds where some albums are fully synced, others partially, and some not at all. 

I followed the download and setup instructions, toggled sync on PC and phone. As I’ve over 400 albums, I’m not going through to try and associate each missing track (especially as the majority of the ones I’ve tried have said that they have not been synced). The bulk of these albums are from CDs that I have uploaded to iTunes and some downloaded from other platforms rather than downloaded purchased items from iStore.

-Is there a way of syncing smaller groups of albums or playlists in case the amount I’m attempting to sync is causing it to stutter?

-Am I missing something glaringly obvious in the settings?

-Just bin Apple Music as not fit for purpose and go back to my iPod?