Help to return all my songs back after new update of iTunes

Okay so I updated the newer version for iTunes 11. 3.0.45 as well the newer version of Window 8 and click 'Update and Restart', now I may have or not had iTunes open at the time but I had a feeling I did this before and never gave me problems expect of recognizing my device and once it restarted cause , I log in into my account and open iTunes to put new songs into my iPhone 5s but it only shows songs that I have purchased!!! And I have no idea what to do because some answer for other people who had the same type of situation said go to your iTunes library and rename your iTunes library to corrupt etc etc but the flies names doesn't match up and if i tried it, a message would popped out saying to 'Try Again or Cancel'. I have no idea what to do as well how to put all my songs that i have download for the a year, it was roughly about 5,000 songs in my library and can't find then in iTunes. PLEASE HELP!!!