I'm not a doctor but my opinion is to stay away from all antibiotics!! You already said your colon is not working. If your gut is not healthy (which gets destroyed from antibiotics), then the rest of your body is falling apart. Every part of our body is connected.
It also sounds to me like you have toxin overload and need to do some serious detoxing. Get those poisons and toxins out of your body and you will feel sooooo much better!!
In the sticky thread on top called "New to Lyme? Start Here!" there are detoxing instructions.
Get in the habit of taking a detox bath at least 5 times a week and please dry skin brush your body before getting into the bath. I don't know what your diet is like but maybe you should rethink your diet. Processed foods are the worse. Start reading books and learn about detoxing and herbal protocols. Perhaps start looking for a Lyme Literate Naturopath Doctor.
I hope this helps,
Totally healed for 8 years ~ used Dr. Jernigan's protocol from his book "Beating Lyme Disease"
Our bodies are wise as they can heal themselves with some help plus detoxing daily, eating healthy. I come back to help others for others helped me when I was sick. Pay it forward!