Hello Anne!!!!
I've been on the Max(that's what I call it). I was given it as a mood stabilizer when my doctor thought I was bipolar. I was on a lot of different meds at the time, which could explain why I felt like this, but it didn't really give me insomnia. That doesn't really say much though cuz I was taking prozac, welbutrin SR, and zyprexa at the time also. But I could imagine it giving you insomnia. I think it was that one that also doubles as an anti-sezure medication(commonly used for epileptics). It would make sense that something like that would keep you up all night.
Now for question number 2!!! I kinda always gained weight on my meds, but I stopped topomax before I stopped the others, and my weight gaining spree did get a little worse. So I'll say that unless your taking other meds that you will probably stay around that weight for a little while.
Now it's time for me to ask YOU a question!!

Have you talked to your doctor about going off the MAX? My doc said he would gradually lower my dose until I was mostly off it anyway. Like weening me off it. Something about possible health issues if I just stopped taking it. Well, I did the logical thing and just stopped taking it. Just kinda wondering if your doc said anything about that, or if mine was just trying to scare me into remaining on it. Probably doesn't matter...I feel like I have the energy of a bear that has the energy of TWO bears!!