I am missing songs! what is going on?

I discover as I go to listen to music THAT I'VE HAD FOR YEARS! it is gone. Last week I discovered that out of easily 10 CDs I only had one and a few individual songs of Billie Holiday. I THINK they are the few that I purchased at the iTunes store and that the ones that I put in iTunes from my personal CDs are GONE! they come anf go: that is I got them back last week after hours on Apple Support. Tonight I went to listen to Judy Collins sing "House of the Rising Sun," GONE! Joan Baez version, gone, too! I think it has to do wiyh iCloud. I hate iCloud! Thanks for any help that anyone can give me!