I would definitely get a second opinion.
I agree with Ree -- it is a sad fact that many/most infectious disease (ID) docs are clueless about Lyme. The main ID doc group, Infectious Disease Society of America (IDSA) is controlled by 'Lyme deniers' who think Lyme is like a summer cold.
If you need help finding a Lyme specialist, let us know what geographic area you are in, like "Nebraska" or "St Louis MO" and we can maybe find some links for you.
Hang in there, and good for you for not just accepting getting blown off by the doc.
I would ask for a copy of your test results and seek another doctor who is Lyme literate!!