on your first question - yes it is very normal to react badly when things like grains/dairy are re-introduced, many poeple are intolorent of foods they eat all the time but they don't really notice as the symptoms are there all the time and the body stops reacting as much with continual exposure (intolerent is normally considered a gut reaction, as opposed to an allergy that is a histamine reaction in the blood and often gets worse each exposure). Some poeple find they can re-introduce things like butter or cream after a time off to heal the gut, others find they need to aviod that food for ever - I think I am finding the later with wheat (but as I don't want flour based products that's fimr with me).
You know all those pictures of Adam and Eve where they have belly button? Think about it..................... take as long as you need........................