Bless your heart. This has to be really difficult for you. Yet, your withdrawal symptoms could be so much worse. Actually, you are lucky just to have insomnia. How often are you reducing the dosage, and how long have you been withdrawing?
I know it's very disconcerting, but try and not to dwell on the insomnia, it may only get worse if you do. Have you tried meditation and visualization? Also, are you withdrawing under the supervision of a physician?
Hang in there, withdrawing from these drugs is not always easy.