Tylerrose... as you can see, Carnival (as well as all the major lines) is well prepared to handle your issues. Sandy provided you with great information, follow it and you will be fine. One thing she didn't mention, that if you do use a CPAP machine, bring an extension cord maybe a short one with the multiple outlets on the end. There is one one outlet in the cabin (and one for razors in the bath) and you may need the x-cord to get the machine located where you want it.
Have a great cruise!
We did the Alaska cruise... it was wonderful and you should enjoy it. But you are doing the right thing and taking a shorter cruise to verify if you like cruising (you will become addicted). Carnival has REALLY comfortable beds. Cruising is a lot like going in an RV except you don't have to worry about driving, how to get there... when will you get there, were will you hook up, no cooking of food or finding entertainment etc
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013