Hi zodiac, I have taken gabapentin in the past, for nerve pain, but I have never heard of anyone taking it for sweats. I remember I started off at 100 mg three times a day, 300mg does sound a high dose.....as you say, go back and see your doctor. I stopped taking it because of weight gain.
I take pregabalin ( or Lycra) now, a similar drug, but once again mine is for nerve pain..... and so far no side affects, apart from not being able to loose weight. both drugs are also used for restless legs, and seizures, amongst other things......
Let us no how you go on.........