Hi,
You probably ate too much at one time. You have to make sure you cut your meat very,very small and chew it very well. You will find that chicken may be hard to digest now.. I know I have problems with that. You must eat slow and chew. They say you should cut your meat the size of a pencil eraser. I know it gets crazy, but it does work. As soon as you get that feeling of fullness, even though you did not eat alot...you have to put the fork down and stop. Some time it passes and you can start to eat again, but sometimes you really are full, believe it or not. It doesn't make sense, but you learn as you go.
I hope this helps you out.
Take care.