Time for Dave's reality check.
So making a lawyer wealthy helps you in which way? I say that because a class action lawsuit means you and any other passengers get a future cruise credit of maybe $200 from NCL and the lawyer gets his 40% of the total settlement. Sorry this happened, but as an RN you should know that this type of illness is usually caused by other infected passengers spreading it - often by boarding the ship ill - and not by the crew. Once present it can be hard to kill despite many cleanings.
Unless you have more than anecdotal evidence - which is what you have (you thought the food was not hot enough, you didn't think the crew changed gloves often enough) - you have nothing a lawyer would be interested in. My advice is to get over it and move on. I hate that it happened to you, but it happens. It happens on ships, in hotels, in hospitals, and in restaurants. The difference is ships are required to report any and all outbreaks to the CDC.