Xanax Withdrawal after 5mg for three years

I have been on .5mg of xanax for three years. I split the pill and take half in the morning and half in the evening. My doctor told me it is time to go off of it. I now take .25mg in the morning and am trying to skip the nighttime dose. The past week I have not been able to sleep only 3 hours a night. How long does it take to wean off of this stuff? Not sleeping is a killer. This stuff is terrible to get off, even a small dose like I am on.

Thanks