Welcome to HW!
Your doctor is being hasty in removing your medications and dismissing your ANA - once you've been diagnosed with Lupus there should never be any going back.
Any way you can get back to the original Dr? If not, I would try to get copies of lab reports (if you don't already have them) showing the positive ANA (remember the number? it makes a difference) and also the full CBC that will show the inflammation markers in the blood.
Take these lab reports, including written info on the meds you were given and the positive results you observed from the meds, to another rheumotologist and get a second opinion. (Although, on second thought, is the current or former Dr a rheumy, I don't think you indicated? Rheumy is who really needs to be treating you.)
To make sure you find a rheumotologist who is up-to-date with Lupus, I recommend finding your local chapter of
www.lupus.org and find which local Drs on the the advisory committee.
Best wishes,