I agree that this is way too close. You'll also have to go through U.S. immigration, and the timing is unpredictable on that one.
I plugged your cruise information into the form that MCPayne provided. The latest arrival time they suggest is 12:30. So, you are already a half-hour past that, and they might not account for the immigration procedures I mentioned above.
Even if everything goes smoothly (and, from experience, flying during winter can mean delays), it will be extremely tight. My suggestion is to pony up the change fee and either take an earlier flight or, better yet, fly in a day earlier and spend the night in a hotel in or near Tampa.
Please keep us posted.