Your consultant or GP will no doubt have told you not to go on a GF diet until your scope is over and you have the results as going on the GF diet now will affect your results.
I have coeliac disease and was diagnosed about 15 years ago. Best advice I could give you would be
not to buy special cook books
- they are often full of hard to find ingredients. Instead just cook whatever you fancy with GF ingredients. Buy some GF flour and cornflour, zyntham gum for baking, GF baking powder, GF pasta ( tesco own brand are good- the fusilli ones or Bulalun GF spaghetti), and away you go. For me I wouldn't bother baking bread, I've tried loads of recipes and it's never great, I buy the odd ciabatta roll GF or juvela fibre bread but wouldnt bother otherwise. Once you get the hang of it life without gluten is no problem at home- in fact it can be healthier than most peoples diets. EAting out is a problem but you get to know good restaurants and you'll get the hang of it.