Hi, have you disabled the defaulted auto-sychro function of ipod? the ipod will automatically sych with the itunes whenever u connect to a pc, so the content will be replaced by different PC u connect to. is it because the pc u connect to is a empty itunes so it was empty in your ipod now?
1.) u can try to access your ipod with another windows pc/Mac using itunes.
2.) u can try to access your ipod with a windows pc/Mac using 3rd party software which allows u to extract the songs out.
Using method 1 , if u are able to access, use a 3rd party program to extract the songs out before restoring your ipod. If neither is able to work, then no choice but to restore to factory settings & look for the songs again.