Hi abanana07. The Doxy dose you were on was in the treatment range for Lyme. Are you sure the Cefuroxime dose was only 100 mg twice daily? I believe the recommended dose for Lyme is 1000 mg twice daily.
I highly recommend seeing a Lyme knowledgeable doctor for an evaluation. If the infection is still present, which sounds possible, the sooner you get properly treated the better. It sounds like you started treatment early in the infection, which is good. Early infections are the easiest to cure.
If you need a doctor recommendaiton for your area, you can email me at email@example.com
In my opinion, it is important to learn as much as possible. I recommend readind Dr. Burrascano's Lyme Treatment Guidelines at http://www.ilads.org/files/burrascano_0905.pdf I also recommned the follwing books: "The Lyme Disease Solution" by Kenneth B. Singleton, "Everything You Need To Know about Lyme Disease" by Karen Vanderhoof-Forschner, and "Healing Lyme: Natural Healing And Prevention of Lyme Borreliosis And Its Coinfections" by Stephen Harrod Buhner.