iPod Touch problems :( please help

I have had my iPodTouch for just over a year now. It has always worked perfectly and I have had no problems. Up until now. I plugged it into my origonial computor that i set up my account on and it said there was an error and i needed to restore my ipod off of itunes. I did that and now it refuses to sync any of my music, apps, or movies in my library. It says my computor doesnt have autorization??? I dont know what that means> will somebody please help me. I need this sorted ASAP 😟