hey guys im a bit inexperienced at modding my xbox but i have tried to download all three DLC’s for skyrim, then inject them into a USB and load them onto my xbox 360 hard drive. this has all worked fine and i moved them over to my xbox. however when i tried to load the game it froze on loading downloadable content. i realised that maybe on of the files have been corrupted so i wiped them from the hard drive an redownload them onto my computer. just to test it again i downloaded only one dlc onto my USB and then onto my xbox which was the dawnguard DLC. when i loaded the game it worked fine and the loading downloadable content did not freeze, however when on the start screen there was no addons tab so i thought it may be because i only have one DLC downloaded so i doesnt need to show a list. i tried going onto the game and starting the quest that takes you too the Dlc content which was talking to a random guard and they give you the quest to get to dawnguard. i tried for an hour talking to as many guards as i can and trying to do other ways to start the quest. this has really bugged me and i would really appreciate some help 
Thanks for reading my post and hopefully getting a long needed answer
thanks!