Hmmmm.....I was trying to figure out your diet. It sounds similar to an antifungal diet that I experimented with, and still try to follow somewhat to keep my UC symptoms away. So, you can eat low carb/low natural sugar fruit and veggies, poultry/fish, (any red meat allowed?), no artificial sweeteners except Stevia, no milk (can you eat butter or plain yogurt?), no nuts (can you eat almonds?). I know it sounds next to impossible to abstain from processed foods and grains, but it really is not that hard once you start eliminating them from your diet. The hardest part is meal/snack preparation because now you have to do a lot more planning and it takes more time to prepare meals. I'm thinking that eventually you will be able to introduce grains/other fruits and veggies back into your diet?
For me, following such a regimen (along with natural supplements) gave me a symptom-free/med-free life. From the sounds of it, you probably have a fungal problem, having taking antibiotics for your infection. I see the reasoning behind the diet advised to you. So I would, as a friend, recommend you experiment with the diet. Within a few weeks you should be able to conclude if the diet will be able to help you. The next 2 weeks will go by whether you experiment with the diet, or not. Wouldn't you rather be on the other side of the 2 weeks being able to reflect on whether this diet will help you, or not :) Good luck to you.