Itunes - need help please!

well i just started using my ipod again and i have a new computer, so i had to wipe my ipod cause itunes is gay (most my songs wern't bought off itunes). Anyways, i made a playlist in my itunes and put all my music in that. then plugged in my ipod and put that playlist on my ipod. i take my ipod out and my playlist is still there. I listened to music for a wile then left. Now i restarted my computer and that playlist dissapeared and idk what to do, it did this twice now and i have to re-download all my music (i backed it all up into a folder after the first time) but still what am i doing wrong? thanks

 

add you music to a folder on your computer (i use a folder on my desktop called "music") then go into itunes, File > Add file or folder > add your music folder

 

yeah sounds like your deleting the music files from the folder. but if you need to get your files off your ipod just use a ipod 2 commputer transfer or if your mac use sentui or something