I’ve done many elimination diets to get to the bottom of my digestive problems/eczema. When I try to add a food back in (especially if I love it), I get anxiety that it's not going to work. How to approach the re-introduction of foods in a better way?

Managing stress and fear when healing the body and learning how to trust it is a big aspect of this, and I really suggest you do the affirmations by Louise Hay in regards to Eczema. So much of it is how we think about it and how we approach it. Try one new food at a time with a reasonable portion and try it twice. After the pathogen purge, your body should shift and you should be able to handle foods you otherwise couldn’t before.