Cathie,
I just restarted this last week. I am also really sensitive to medication and had only ever taken 300 mg of this at bedtime. This time my doctor gave me the 100mg and had me take 100mg at bedtime for 2 days, then add a morning dose for two days, then add the afternoon dose for a total of 300mg. She said if I felt drowsy with the afternoon dose, back off again for a couple of days and then try again. If it was too much to move it to the bedtime dose.
I cannot believe it, but I have not had any problems so far and it is not even making me drowsy. Next I go to 200mg at night and then up the other two doses if I can. Definitely see if your doctor can lower the dose and try again. There is no reason to feel worse!
I wish I could say it is working, but I can't tell a difference in my pain yet.
I hope you get this worked out and feel better!