Shoebox symptoms and conditions

Hi there. A number of years back--maybe 8 or 9 years, I was prescribed Topamax for bulimia and mood swings. I was on a dosage that eventually went as high as 75 or 100 mg. At first it improved my mood and decreased my bingeing, which was very encouraging, but I began to have really awful side effects. First was the cognitive stuff: I couldn't remember people's names and even simple logic puzzles like how to fit a pair of shoes into a shoebox correctly stumped me. Soda tasted flat. Then my moods became somewhat erratic and I began to have intestinal discomfort. Then, even more oddly, my skin started having trouble healing from minor wounds. My hair became brittle and began to fall out. At that point I gave up and stopped the medication. It really felt like I was undergoing some kind of slow poisoning, like arsenic or something.

Now, I've developed migraines and my neurologist has put me on a small dose of 25 mg at bedtime. I've been highly reluctant to acquiesce after my former experience but nothing else has worked and I sometimes have headaches that last over two weeks at a time. I'm wondering if anyone else has experienced side effects at 75 mg but not at 25?

Hopeful in NY