Fruit fast - your initial relief is something we have many times experienced here on a fruit fast. For me it took three days of fruit and water, so you are quite lucky to get there on day one! A good sign that your body is able to right itself quickly once you get your diet right.
Just remember that you can repeat this any time! One or two days of grapes oranges pears apples melons papaya and water. After that you can test food one by one and see how you go.
Dairy - as others have said .. it is a problem for many. Yoghurt and cheese is better but even then it can sometimes be a problem.
Have you gotten the hang of baking using almond flour?https://sites.google.com/site/cureankylosingspondylitis/recipes/almond-meal-recipes