gives me a status code 80150101 everytime, says "cant download items" so pissed...any help with this?

Just keep hitting the download again button. Worked for me.

also says my cloud saved games arent available..

Can you go to marketplace, then go to Dawnguard and hit download again then?

It is probably a bug(concerning the cloud saves). They will probably work again given time.

i kept hitting download again and it is downloading now, but cloud saved isnt online it says and thats where my guy is!! But what do i do after it downloads?? do i need to install it to the game or what?

I went to xbox.com and added it to my queue there, and when I turned on my xbox it downloaded fine.