Q: I own a PC and had 21 plus days of music on my PC. Then my job gave me a company IPhone Mobile Iron and soemthing happen that corrupted my iTunes collection. I had ! points next to all my songs and was unable to play my music that I had uploaded. Help!

I had 21 days plus of music loaded into my iTunes on my PC> Then in Feb. I was given a Mobile Iron iPhone from my job. When I uploaded the phone on to my PC I suddenly found that my music files were corrupted and I could longer play the songs I had in my PC. There was an ! point next to the songs stating that the song could not be located. I tried everything possible to access the song location and even copied the files from my back up drive to iTunes. No good. I would up losing the music I had on my iPod and now I have nothing. As per the direction of someone I know with extensive experience with iTunes I uninstalled the program and then tried to re-install it but have been unsuccessful.... I am totally upset about the loss of all this music.... Help me if you can...