I do hope you understand, Carolyn, that if you DO have MS, the common treatments for MS (Copaxone, Avonex, Betaseron, Rebif) are not cures, and won't alleviate any symptoms. You'd have to continue to take other medications that might help some symptoms, but they won't make them go away entirely, either. Minocycline is used in some very limited instances for people with MS, and isn't a cure, either.
MS is not an easy disorder to diagnose. It's considered a "diagnosis of exclusion", meaning they'll rule out everything else before declaring it -- which is going to be complicated in your situation, since you're dealing with the brain tumor and a possible chronic infection of the central nervous system (whatever it's cause -- Lyme, or something else). I'm sure your doctor is trying to sort through all that. It is not hereditary, in the sense of other inherited things. There is some genetic predisposition -- that is, some people with MS have other immediate family members with MS, but certainly not all. And some people with MS have other family members with other autoimmune disorders...but again, not all. There are lots of us who are "blessed" with being the only one in our family with the disease. There is no known cause of MS, and no cure -- only the meds that have shown promise that they'll reduce the number and intensity of flares, or exacerbations of the disease.
The common drugs for MS (Copaxone, etc.), are all injectible medications, by the way. You will learn to inject yourself on a schedule for that medication -- some are daily, some weekly, and so on. They are expensive, too -- around $800-$1,000 per month, generally covered by health insurance (if you have health insurance that covers prescription medications).
I hope you can at least get closer to some definitive diagnosis and treatment over the next few weeks as you undergo this new round of testing.
...I am not a doctor, nor health professional, and don't pretend to be one, here.....