I find I have the hardest time on the weekends, when it seems like there's a million things to get done but no schedule. During the week, I get up early (while kids are still asleep) and make breakfast, pack a lunch, and check to see that I'll have good dinner choices when I get home. The workdays are actually so much busier, but the routine keeps me on track. I'm working to incorporate that structure into the weekends.
The supplements do add up, but in the long run it will be cheaper for me to take them, stay on program, and finish this in my 17 weeks. The more I cheat, the longer this will take, and I'm determined not to pay for more weeks. One of the counselors asked how I handled temptation over the holidays, and I just figured, "I've eaten whatever I want my entire life, and look where that got me. It wont kill me to go one Christmas without a cookie." This is such a short time out of my life, I can commit.
Good luck--you can do it. You have a lot of responsibilities, but one of those responsibilities is to yourself.