A Very Frustrating Occurrence

I updated to 6.1 on my iPhone, mainly so I could download songs from iTunes Match. I have a lot of songs in iTunes Match but I only wanted certain ones on my iPhone so I could play them without having to use my data or if I could not access wi-fi. For the past few days I have added songs at various times, downloading over 300. I added two songs (one by mistake) just about 15 minutes ago. When I disabled iTunes Match and went to my library there were only two songs that I had (the last two I downloaded). I have no idea how or why all my other songs got deleted but I am certainly frustrated over what happened. Needless to say I will not be downloading any songs to my iPhone anymore.