The tests you list (the IgA, IgM, IgG) are not specific to Lyme. I think what these tests are showing is the total IgA, IgM and IgG in your blood. This is a generic measure of your immune system and since your numbers are in the normal range, they only tell you that your immune system is not over or under-active in the production of antibodies of these types.
CRP and SED rate (ESR) are generic measures of inflammation in the body, but they do not tell you where in the body the inflammation is occurring. Many diseases, including Lyme and other infections, can cause the kind of inflammation that will make these numbers go up, so knowing these 2 numbers alone is just telling you something is wrong and not telling you what that something is.
I don't know anything about Strep titers, but if I had to guess, I'd say that you were a symptom-free carrier of the Strep and that may be why you have the high titer without symptoms. It may be sequestered by the body in that lymph node that is enlarged.
Sounds like you need to find another doctor who will take you more seriously. Rheumatologists may not be the right kind of specialist. A Lyme-Literate physician may be able to help figure out what is going on - Lyme may or may not be what is at the root of your symptoms, it is hard to say. But a lyme test (IGeneX Western Blot is best) would be good to get done. You can post the results here and we can help you figure out if you need to see an LLMD or not based on the results (we can't diagnose you but we can help to point you in the direction to go if your test results suggest Lyme is a possibility).
I hope this helps - take care,
Chronic Lyme Disease, Bartonella (clinical dx only), Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, etc.; G-Tube; TPN via PICC (trying again to wean off the TPN).
Meds: IV Cipro, Heparin (to flush PICC line), Singulair, Claritin, Domperidone, Colloidal Silver, probiotics, digestive enzymes, Milk Thistle & other liver support herbs, Magnesium, homeopathy.