PS You don't say what state or area you live in ... if you would let us know something like "near St Louis, Missouri", we might have some suggestions for you of how to find a Lyme specialist in your area, if your current doc isn't familiar with Lyme. Hang in there, and keep us posted, okay?
I never had a rash so was misdiagnosed 25 years. You need to get more abx if you regular doctor can't give you at least another month of antibiotics then I would see an LLMD, Lyme literate Doc. This is no joke, take it from me, it can turn chronic and make your like miserable as it has done for me.
You can ask to be put on the doc's cancellation list ... tell them how much lead time you need to get to their office, and ask that they call you when a slot opens up, or if they can recommend another doc nearby. Take care!
I definitely would pursue lyme if the antibiotics are helping. I have not yet been able to try any my self. Still must wait 6 months for an LLMD
Did you have any testing fro lyme yet?