Your body is changing over from living on outside nourishment to surviving on it's own reserves. This process can take up to five days from the last food eaten before it is comfortably supplying all your needs. Most people start feeling better from about 3 days though.
The more you can stick to raw foods after your fast the better off you will be. So apart from those things and seeds and maybe a bit of dried fruit for variety, only add other things in small quantities and add them to your salads later on in the refeeding process.