lovin diz, I'm from the Pensacola area and was over in Bay St. Louis earlier this week. It's probably no surprise to you that there's not any gas to be found on the I-10 corridor through most of Mississippi, but I believe it looked like business as usual by Pascagoula, and I know for sure you won't have any trouble from Mobile onwards.
I also think you'll be fine in Florida. Have a great trip!