IPod Files Lost

Hi!
So last night, my itunes said it was getting overloaded so i started recycling a few old files which i then proceeded to delete. then i deleted a couple of programs that my computer said that it rarely used. when i restarted it, my itunes would not play any of the songs as it said the original files could not be located. when i searched music on my computer, the only files it can pull up are ones purchased through emusic, none through itunes or cds. i know that if i sync the ipod to the computer i will lose everything, so what do i do from here? i saw there are some programs online for recovering lost files to itunes for seventy dollars, but these are probably a scam right? in that case, is there a way to perhaps back up the hard drive on my ipod which still contains all of these files so that if my ipod breaks i do not lose everything? that is what i am most worried about. if i have to buy a new ipod and start a new library i could deal with that, just as long as i know i am going to have the old files.....any ideas?
thank you so much......