Did you have an epidural when you delivered your baby? There are a few women on one of the other boards-neuromuscular or brain and nervous system disorders who were sharing (I'm sorry, I honestly don't remember which board they were on...) that they'd had similar symptoms after childbirth and one woman said she found out it had something to do with peripheral nerve damage from an epidural-but peripheral nerves can regenerate, so don't let the word "damage" freak you out. I think another had said it could be from the baby compressing the nerves of your lower back during delivery-even without the epidural. In fact, the pelvic girdle joints relax quite a bit during pregnancy, so I'm not sure this isn't related to that as well? Do you have any bladder/bowel function issues? If so, it is considered a medical emergency and you ought to be seen in the emergency room to rule out cauda equina syndrome.
In fact, here is a link that I found concerning injuries that can occur during normal childbirth and with epidural anesthesia. http://www.oyston.com/anaes/local/muir.html
MS can also be exacerbated after childbirth, from what I'm told.
It certainly bears looking into. Have you ever had eye symptoms or anything else in the past?
The first step is to get yourself to a neurologist and get an mri of the brain, also get a nerve conduction/emg of your legs to make sure there hasn't been any damage there.
Blessings and prayers to you.