Hi, I'm sorry you're in so much pain!
I don't really get electric shock pains, either. But before I started taking medicine for it, (it's called neurontin or gabapentin,) I'd have attacks where I felt like my face was being stabbed or something. I guess maybe other people would describe it as an electric shock. I don't know. But now that I take medicine, I only get an ache in my jaw and teeth that gets better or worse. So I guess everyone's a little different.
I bet you've already tried this before, but does heat help at all? It helps me somewhat. Like microwave a damp washcloth until it's very warm. Or you can use one of those pillows they sell that have rice or something in them that you can microwave, that stays hot longer than a washcloth. Both of those things help me. There's someone here that said that icing the area helped, but that sounds really painful. I guess it's just what your body would respond to.
I hope you find something that helps! If the topamax never starts helping, you should ask your doctor if you should take a different medicine. Because I had been on it for migraines (probably caused by the trigeminal neuralgia) and when the migraines had stopped, the doctor told me to stop taking it. But your doctor knows better than I do! It's still worth an ask.