why won't my music work?

I have an iPhone 6. After about 1 month of usage I noticed how poorly my music app was functioning. If I place my phone on shuffle mode, it plays one song and then stops. Also, if I try to skip songs on shuffle mode my phone will automatically crash. In addition, it will not play songs I want to play. It skips over them. I click on the song, and it shows it for two seconds and then plays the next song. Please help!