Hi Starlet,
Sorry to hear you're having such problems when you really want to be enjoying those beautiful babies so much more than you can right now feeling so crummy.
Unfortunately, doctors seem to go the "you're depressed" route too often and too quickly. Since you're a new mom its even easier to blame your fatigue, etc. on the 'baby blues'. But you know your body and its up to you to pursue this. If your doctor can be nudged, get him to prescribe all the tests: MRI with and without contrast, lumbar puncture, bloodwork including lyme & lupus, urinalysis, etc. Better yet, if he could speak directly with a neurologist he may know, that might be the 'in' that could get you in the door and listened to. Your regular eye doctor should be able to see if you've got an issue with the optic nerve, but would probably send you to a neuro-opthomologist for treatment, who then might suggest a neurologist.
I assume your doctor is aware of your Mom's MS? I would think that that fact alone would put him on high alert when you describe your symptoms. Hopefully you can work with this doctor you've known for so long, but if not you might have to consider going elsewhere for help. I'm sure that would be difficult, but it might be what's needed to find answers.
As Jewel suggests, keep a log or journal of your symptoms so that when you speak with your doctor(s) you don't forget anything that might help them in their investigation.
Take care, kiss the kids,
Dee