Hey Amanda, don't beat yourself up too badly. You've made a plan to get back on track-just work your plan. I too went out of town on Sunday and ate badly, "Well back to plan on Monday" and off to McDonalds I drove :( Well, I've done good at lunch and hope to for dinner. SIGH. Weekends are hard.
Oh, I found Crystal Light carries a margareta flavored powder. I've bought some but keep forgetting to buy tequilla. I drink martinis (non-flavored) or whisky and diet coke, and everyone seems to respect my choice. As long as I bellied up to the bar with them, they don't care as much WHAT I'm drinking.