Hi. 2 days ago I bought a cd ATB. And yesterday I deleted everything from iTunes. Please help in recovering all purchased cd

Did you just delete them from iTunes, or did you also tell it to delete the music files from your Mac ? If just from iTunes then they might still be stored under /Users/username/Music - if they are then you can add them back via File > Add To Library

If not, then whether you can redownload music depends upon what country that you are in. If you can redownload music (and if you haven't changed countries since buying it and it's still in your country's store) then it should show under the Purchased link under Quicklinks on the right-hand side of the iTunes store homepage :

If you can't redownload music then do you have a copy of it on your backup of your downloads/library that you can copy it back from ?