I've had a rash for about 3.5 years now and have been gluten free for 2.5, low iodine for a little over one year. My skin seems very sensitive to the amount of iodine I eat, and I have occasionally gotten to a really great point of healing and clearing before managing to muck it all up by going on holiday or something. Of course, then it's like being back at almost square one again for the longest time.
As far as I can tell you, it does seem to have an ebb and flow that sometimes seems to not correspond to anything you are doing/eating. It really is the most frustrating thing I have experienced. It's still early days for you, but it sounds like you are really responding well to the changes you've made. Don't lose hope. Keep up what you are doing because it should work, even if there is no clear timeline (it's different for each one of us). For myself, I've been thinking about trying hypnosis to help stop scratching and picking at my skin. I can see that I'll be covered in scars at the end of this. If I was ever vain, this has really helped me become a more humble human being.