Problems putting music on my phone

I just spent 3 hours putting music on my phone using Verizon Backup Assistant Plus. There were two drives to put it on, my phone and the SD card on my phone. I filled up the SD card first and then put some on the internal storage of the phone. Then I went on my phone to check if everything transferred and a lot of songs didn't. But, there are a bunch of songs on there from my music collection that I didn't even transfer to my phone. I've had nothing but trouble with using my phone for music but it would be nice to have everything in one place instead of using an mp3 player as well. If anyone can help me or has any suggestions? When my phone is hooked up to my computer, it says all the songs i put on there are on there...then I disconnect and look on my phone and it's all messed up. PLEASE HELP!