You'll hear this said on this website over and over again, and I believe it may be the best advice you'll find: Motivation comes and goes. Commitment is the key. It's about deciding what you want to do and sticking with it. That doesn't mean not falling down. It means falling down 9 times and getting up 10.
You said it's a shame you can't eat healthy for a week straight. Neither can I. I can't do whole weeks at a time. I can only do one day at a time. There's a reason why this concept is the cornerstone of the twelve step program.
You can do this! Make your plan and work at it every day. Learn from your mistakes and change your plan as necessary. Rinse and repeat.
I look forward to hearing about your successes!

