Sorry to hear you have had symptoms for 8 years! I hope you are on your way to recovery. Unfortunately, Lyme and coinfections are tricky to diagnose and to treat. You definitely need a doc who is experienced with treating them (an ilads affiliated doc) and who knows how to deal with a long standing infection.
I have Lyme and Bartonella and I haven't had any muscle pain. I am a true case of neuroborreliosis. The Bartonella has caused me anxiety along with more intense neuro and GI symptoms, which is a common effect of the two.
The symptoms can really vary from person to person, and sometimes it's hard to pin down the coinfection(s), unless there are some uniquely identifying symptoms (like the scratch-looking rash of Bartonella).
Babesia can also be hidden, and can make the Lyme bugs treatment resistant. Have you been tested for coinfections yet? IGeneX is the best for tick borne disease testing.
Not everybody responds the same to any given abx, and usually a combination is more effective. It is not uncommon for symptoms to vary and for new ones to develop after starting treatment. Have you asked your doctor for anything to help with the pain? Epsom salt baths might help. People with Lyme are nearly always magnesium deficient, and epsom salts and supplements can help replenish it.
I have come out positive for Lyme and Bart's and the kind of pain you described is not unusual, everyone experiences the pain differently. The sad thing is there is not one way to treat and not one way that works for everyone . I agree with Jackie about who you see and where you are tested.
Welcome -- sorry you are suffering so much for so long!
Did your doc test you for various co-infections that may come with Lyme, and if so, do you know which lab did the tests? That can make a big difference.
You were positive for Lyme and bartonella?
Also, do you know if your doc is a member of ILADS, the main voluntary group for Lyme specialists? I see that you call her an LLMD, but that can mean a variety of approaches to treating Lyme.