Running on a Treadmill

I am very disappointed in myself today! We had a meeting at work with a lunch that was to die for and of course I ate everything: chicken, mashed potato, mac-n-cheese and green beans. Oh also a piece of pie (that was delicious). Later for a snack, I had a piece of cake. Then when I got home, I dressed and went to the gym with Greg. With a full belly, I walked for 10 minutes then went into a slow jog for over 1/2 of a mile. I finished up walking/jogging for a total of 1.5 miles. Just didn't feel like I could make it any more. However, I did get to see my beautiful sister-in-law and her family! That made my day to the gym! Then I came home and ate leftovers from earlier today. At this time, I feel awful. Not only miserable because I am full but very discouraged that I ate so much. I knew getting discouraged would eventually creep up but just did not expect it so early in my training.