Wowowowo!! hehe that is awesome!! I'm completely jealous right now, of your husband and of your beach trip!
Reasons Not to Freak Out:
#1 A lot of resorts have healthy options.."spa food."
#2 You can take some healthy snacks with you so you don't feel tempted to over indulge.
#3 Portion control = resort food, just less of it.
#4 One week will not ruin all your hard work.
#5 I'm sure SOMEWHERE in Dallas they are still carrying bathing suits since I imagine it's still really freaking hot there. Plus, they are probably on sale since it is the end of the season.
#6 Spray tan! Or tanning lotion. You have plenty of time to work on it to at least take the glare off the white
See, so don't worry! It takes a little more planning, but you'll have a great time!