How can I downgrade iTunes 12.2 to 12.1

I don't think its possible one you upgraded.

IN Preferences > General > switch OFF Show Apple Music and iCloud Music Library. This hides all the new features.

Definitely possible, and that is exactly what I did.

Delete directions: http://osxdaily.com/2012/02/06/delete-itunes-mac-os-x/

Old version is available online, just google it, download and install. Works perfectly for me.