I have had this dizziness happen on several occasions, lasting from 2 weeks to 2 months after cruising. There seems to be no rhyme or reason to when it happens. 4 days on a 110' tall ship left me dizzy for 2 weeks. The only respite was the few hours I sailed on an afternoon cruise (same ship.) The dizziness went away completely while we were at sea. The 2 hour drive home was hell! Another cruise on the tall ship, including 2 days with high seas- no problem! 14 days, same ship- no problem.
First cruise on a regular big cruise ship- 4 day Mexico trip on Carnival- I was down for almost 2 months. After the next trip it was only a few hours. After 34 days last year on the Pacific Princess- didn't miss a step. Go figure. We are headed out for 14 days on the Millenium the end of next month- I hope that perhaps I am beyond the problem. I AM glad to have a name for the problem, just in case it happens again. I have no intention to give up cruising!!