Discouraged

I am having a real bad day today. Yesterday was day 4 and at the last minute of the day I had to prepare dinner for 6 guest. I was cooking up a storm and was doing well...never taste tested anything, and really not even much of a desire to do so. I made it through the evening and stayed true to the MC, but was exhausted.
This morning, day 5 I was still exhasted. My stomach was bloating again as well. I had many errands to run and when I was out buying Mothers Day gifts, I felt I would just about pass out! I got myself home, drank some lemonade and the urge to eat hit me hard.....and I fell for it and gave in. I ate leftover tossed salad I made from last night, a piece of bread and a half of a twice baked potatoe...then...I crashed. I could hardly stay awake.
Anyway, so now I'm up and wondering now what to do? Is it okay to return to the MC? If so...am I back to day one? I feel bad I gave in to food. I was doing so well untill today when I was out shopping and nearly fainted. I do drink lots and lots of purified water. Is this normal? Otherwise I have not had much problems on the MC. Maybe I just have a ton of toxins in me?
I have to have this fasting over by the 13th, due to family reunion and wedding coming up for a friend. Maybe I should wait till after all that and try this again? I really want to do it now though since I have come so far, 5 days....I was halfway to my goal of ten. Feel like a failure, especially after reading post of those of you who are hanging in there. UGH! Any advise would be helpful. Thanks~Sara