canuckchic, don't think of this as a failure but more a learning experience.
Do you know it took me 5 attempts to quit smoking? I felt like such a failure each time I lit up a cig. Then one day while surfing the internet I ran across the American Lung Association's web page. I found something there that actually gave me hope.
Their advice was this:
Don't look at the times you have tried to quit smoking and went back as a failure but a learning experience. Write down what is going on in your life at the time you went back.
Try again. Look at the previous times as "practice sessions" You will quit.
I learned the same applies a lot with food addictions. Don't look at this as a failure but more of a learning experience. Maybe instead of going full out you can cut out the carbs a little at a time.
Do something like this:
For the next two weeks just give up bread. Then the following two weeks give up pasta or rice. Then give up sugar. Give yourself a couple of weeks between to wean yourself slowly off. Pretty soon you will be pretty much carb free except for the healthy carbs coming from veggies
Another thing that may have occurred to cause your fainting spell may have been hunger or dehydration. This is not a starvation diet. Make sure you eat very well and drink lots of water
Give yourself a pat on the back for your first attempt, keep your chin up and try again