There are many reasons why people don't heal quickly - a couple of the most common reasons that I have seen can be because they haven't found the right combination of abx, or they need to treat one of the other infections/conditions that they have first.
I agree with Girlie in that while diet is an important part of healing, a diet that isn't too bad wont' stop the healing - won't help it much, but won't stop it. I healed from a 40+ yr infection in only 12 months and although I had a healthy diet, I certainly didn't follow a Lyme or Candida diet during that time.
You may have other conditions that may need to be treated. I assume that most of us go through sooo much testing trying to find out what's wrong with us pre Lyme diagnosis. Take a look at your labs and other paperwork that you may have and see if there are any clues there.
This site has so much valuable information when we can't seem to make much progress. It's from a rather famous LLMD, Dr. H. I would encourage you to spend some time looking it over to see if something there makes sense for you:
http://www.cangetbetter.com/