Yikes! So sorry you live in an affected area, that has to be stress inducing, and I'm sure you know stress isn't very good for Lupus. Try to stay in the moment and do one thing at a time. I don't have any great ideas off the top of my head.
Did your Dr have an online portal so that you can see your records? If you can't get in touch with him or his office, you may be able to use the information found there to see another Dr in Jacksonville. I would imagine that Drs there are seeing lots of chronic patients so might have ideas on what to do. I would point out to the new Dr that an interruption in the care plan already established by your currently-absent Dr would be harmful to you.
All I was able to find in searching on line for this situation is a 30-day prescript
ion plan, where the script
is honored for the short term. https://www.aarp.org/health/drugs-supplements/info-2017/emergency-prescriptions-hurricane-harvey-fd.html
If your run into a FEMA office, remember to ask them about
Drs as well as for food and housing issues. They may have better ideas.