No need to apologize I'm sure you didn't realize!
Even through Igenex, testing isn't that helpful - it's one of those things where if you get a positive test, it just makes everything a lot easier, but so, so many people get a negative test or only a few bands who do have Lyme. Sometimes the test will become positive with treatment, as your body produces more antibodies to the bacteria.
My concern is that you're only taking 200 mg of doxy - that'll stop the bacteria from reproducing but it isn't a high enough dosage to kill the bacteria. Maybe bring this up to your doctor? It's my understanding that most LLMDs treat by Burrascano's guidelines - do you know if yours is? It might help to bring a printout of the guidelines with you as I think it lists the necessary dosages - here's a link if you need it (might be helpful in general just to take a look at it!)
www.ilads.org/lyme_disease/B_guidelines_12_17_08.pdfDo try to take the acidophilus regularly - you need all those healthy bacteria! If your stomach is bothering you, you may not be getting enough probiotics to begin with, or enough different strains of bacteria - I don't mean to overwhelm you, it's just something to keep an eye on if you're having trouble with your stomach.
Not everyone herxes, either. Generally the worse the herx, the worse off your detoxification pathways are - sounds like between the exercise, sauna, and baths, your body is doing pretty well!