Q: itunes said it needed to fix something and it eraced my songs and would not put them back now my ipod acts like new with no songs and itunes locks up when connected

I have around 4500 songs on itunes and none on my ipod

when I connect my Ipod itunes said it needs to scan something recomended so I tell it to fix and then itunes stops responding even the task manager will not turn it off just locks up my computer untill i have to pull the plug