I am not a doctor but I am a nurse and have worked in addictions for many years.
Of all of the benzodiazepines Xanax is the hardest to come off. This class of medications is really only supposed to be used for a few weeks while a person learns coping skills. So sort of a bridge to get you to where you are managing your symptoms with behavioral skills. There are also antidepressants that are prescribed for anxiety in their higher doses. Again, a medication in the benzo family might be used as a bridge until the other medication is effective.
The benzodiazepine family of medications hits the same receptor cells as alcohol so it is advisable that you are not drinking while on the medication. And like severe alcohol withdrawal, if you have been taking xanax for many years, withdrawal can be life threatening. Going super slow off of xanax is very important and under the care of a provider. Sometimes we will convert a person to klonopin to taper because it is longer acting and smother to come off or sometimes will prescribe a medication like gabapentin or Depakote when you are coming off to protect from seizures.
Someone mentioned oxycodone. Coming off an opioid is very uncomfortable but is not life threatening.

It is good that you are tapering the xanax very slowly. When you get down to the end you could even take a dose every other day for a week. Keep in mind though that if you have been taking this for years, you may need to evaluate your sleep habits and work on sleep hygiene. This article has some great tips.
https://www.verywellmind.com/how-to-get-better-sleep-5094084
Even when you are completely off of benzo's, it may take your body a few months to adjust so be kind to yourself. Don't lay in bed awake because your body will start to associate the frustration of not being able to sleep with your bed. Get out of bed if you are not sleeping after 20 minutes and sit in the chair doing something boring until you feel drowsy and then try going back to sleep. If you're not asleep after 20 minutes, do it again. (Don't read a good book that you will get interested in. It has to be a quiet and boring activity. Don't do anything activating like clean the house). Repeat all night if you have to. Sometimes people will do this for several nights in a row until your body cooperates and remembers that the bed is for sleep.
Again, be kind to yourself. Nurture yourself and sleep well.