heeeeeeeeeeeeelp

im editing my interview but i have so many problems with garageband and audacity.
I cannot slide the file i downloaded so that i had to copy and paste the background music. when i thought i have completed the project and i tried lisetening to it, some parts of the interview were eliminated somehow...how did it happen?
I spent many hours on this editing so im so dissapointed now. i dont think i can submit this...
whats worse, macs at tuj do not save the files on audacity, which means i will end up with wasting time if i wanna edit at school. I thought i loved this class but now i donno if i can manage this anymore. im hopless and i wanna drop this class.