iTunes has encountered a problem...

Im having problems with my itunes, all of a sudden one day an error showed up saying
“iTunes has encountered a problem and needs to close. We are sorry for the inconvenience.” And then It asked me if I wanted to send error report or don’t send. We are sorry for the inconvenience. I wasn’t sure what to do and thought that it was important to send the error soo I did and still my itunes wouldn’t work soo I uninstalled my itunes and reinstalled like a million times and still noo luck. And I tried my quick times and it days error. When I connected my ipod all my music disappeared. Now I don’t have any music and my itunes doesn’t work. Ive tried itunes on other users on my computer and the same error shows up. I NEED HELP!!!!!!