Hi, and sorry to hear about your situation.
I agree with gorbs that it's tough to offer much advice given what you've told us. Lyme disease is often difficult to diagnose given that it can present so differently and can mimic so many conditions. That and the blood tests are not so reliable. So while it is possible that Lyme or other tick-borne disease could cause your problems, there is a lot of overlap with other conditions so you need a good and thorough evaluation.
Lyme is systemic-meaning that it can affect the heart and the central nervous system and the ears, etc. But again, only a skilled doctor can help diagnose you.
Other than the MRI, what sort of tests have you had, and were any results abnormal? And while I see you are in CA, have you traveled? While Lyme is spreading all over, it is more endemic to some locations.
You are on the lyme forum so I guess you must be thinking you may have lyme - I am not an expert or medically qualified - but in my opinion your symptoms do not fit the 'usual' lyme symptoms but having said that 'lyme' can bring all kinds of symptoms.
Do you remember a 'tick' on you or any 'odd' rashes ?
When we are concerned about health issues we can become anxious which obviously makes us feel worse - my suggestion would be to go to a different doctor and explain that you are scared by your symptoms . The fact that the MRI - showed no abnormalities - should be somewhat reassuring.
keep us posted - gorbs x