sleeplessness

I am presently cutting down paxil from 20mg to 10mg and have been on the drug for the past 10 years.  I was on anafranil before that and have been on antidepressants on and off for 16 years.  I feel good, and have decided to ween off paxil but am having a horrible time.  The most horrible withdrawal symptom is the lack of sleep.  I can't fall asleep and can't stay asleep.  Is this maybe from the underlying illness(anxiety)  it feels like I can't relax when I am trying to sleep and I feel irritable, can't get comfortable.  I have been cutting down for about a month now and sleeplessness has resulted really bad within the last 3 days.  Wondering if I should go back up to 20mg to deal with the insomnia that I have until I can get into see my doctor.  I am one who needs my sleep, and when I don't get it, then I start to feel anxious and panicky.  How long can you go without sleep?  In the past I have suffered depression from lack of sleep or maybe its vice versa?