Get a 2nd opinion. That is what my neuro told me that these spots on the brain can be caused by Migraines however white spots can also be caused by MS. I have both migraines and MS and I have six lesions.
Sometimes it takes a while for a person to be dx'd with MS or ruled out. As they are not only looking for brain and / or spinal lesions but clinical findings, like documented episodes of maybe a leg tingling or numbness in arms when it happened and how long did it last, etc... If you are not keeping a diary / log, I suggest that you begin keeping one. It may seem insignficant at this time but it is very helpful for your neurologist.
Have you been tested for anything else?
You are too young to be having these problems and you need an answer.
~Zig