iTunes music subscription ?

So I used to individually buy music on iTunes and then decided to just pay for subscription so I can get a lot more music. I thought if you had a subscription you basically bought the music, it’s yours to listen to anytime and add to iPod.

Well a couple years passed and I decided to cancel my subscription. Now all the music I have added to my library over the couple years is GONE! I still have the songs I paid for individually without the subscription years ago but every thing else is gone. Does that make sense?

Does the subscription just mean you can listen to music anytime but if you cancel the music you added is cancelled too?

I really don’t want to have a subscription but I want all my music back 😩