how do i add Crysis special edition to my steam account when i only have the CD?

Do you have a code with you for the game?

yes

Try to redeem the code in Steam app on your end.

Hey ashopkinsowo​, 

Since Crysis is an EA game and you have a physical disc, it's likely that you purchased it quite some time ago. With that in mind, not all older games can be redeemed through the EA app or Steam.

You can still try redeeming the code in the EA app, although I don't expect it to work on Steam. If you do try it in the EA app, let me know the exact message you receive.

If the message says the code has already been redeemed on another account, the EA Help team may be able to assist you further.