I agree with Roooth that it will take your body some time to adjust to the program.
I felt very heavy the first week - very "full" all the time. I was also very concerned about what to eat and when to eat.
The second week was much easier for me, much less emphasis on the what and when. I just made sure that I had plenty of fresh fruits and veggies available and ate whatever sounded good to me at mealtimes.
This really is (for me, anyway) learning a new way of eating, so it is natural that it will take your body and mind a while to adjust.
Good luck this week. Be sure to check back and let us know how it is going and let Ruth and Steve and Fasting2Goal know if you have any other questions. They are dedicated to getting healthy.