Liza,
Don't worry--it is normal to have some feelings come up when you begin a change like this. Take deep breaths! Seriously--it's a big adjustment, like GirlyGirl said. And also, you might be feeling some fear! That's also normal. Feel the feelings, don't act out on them, and stay with your plan. Make sure you are getting good nourishment, be sure you get enough rest and drink enough liquids (water is best), and keep going!
You can do this--it will get easier the longer you keep going.
Jay