Infectious disease docs are not known generally for progressive views about Lyme Disease, but it can't hurt to get other possible infections ruled out, since your Lyme test came back negative.
Two preliminary questions, tho:
1--Had you taken antibiotics at all in the time just preceding your Lyme test? Some LLMDs will give a short course of antibiotics before the test, to stir up the immune system and show a reaction on the test that might otherwise be erroneously negative. It's called an 'antibiotic challenge.' What happens is that the immune system stops reacting to the Lyme bacteria after a period of time, and only with stimulus from a short antibiotic treatment will the immune system make antibodies against Lyme, which then show up on the test.
2--Were you tested for co-infections, which are other diseases often carried by the Lyme ticks? Which co-infections you may have are based on symptoms, but everyone is different in what symptoms they display.
As far as I know (and I'm NOT medically trained), an MRI is not diagnostic of Lyme.
Were you seeing a Lyme specialist, sometimes called an LLMD by patients (meaning 'Lyme Literate MD')?
Me too I come up neg with the 2 lyme titer I had and they dont do anything else herein CA unless you find a hugely expensive Naturopath,