Lexia, I don't know if your post-migraine pain is TN or not, but I think (I'm not sure) that the trigeminal nerves ARE the ones that carry the pain of migraine?
Which wouldn't rule out TN due to MS, of course. I have never heard of post-migraine neuralgia. Maybe the migraine exacerbates what is actually underlying TN?
Just a wild guess from someone who doesn't know what she's talking about.

Hope your neurologist can help you find relief. Have you seen a headache specialist?
Linda: your day of stabs that comes several times a year sounds pretty familiar. When I get stabs in the face (or elsewhere) they often last on and off over the course of a day or a day and a half.
Sometimes they are in the corner of an eye, but they aren't severe, just attention-getting. The cheek and ear are more likely spots for me.
Nancy