I read your question carefully and I understand your concern.
I must say that I do not agree with the use you are making of
Xanax. You speak of sleeping without sleeping pills, but Xanax itself is a sleeping pill. It is not a good sleeping pill furthermore because of its long term consequences, so I would rather you took another sleeping pill instead of Xanax really.
Even if your aim is to relieve
anxiety, not for sleep, still it is the wrong medication, the wrong class of medication. I prescribe it for anxiety only when it is something transitory and I predict treatment will be needed for less than a month. If longer treatment is needed Xanax is not suitable, over time it creates tolerance, the same dose will not be enough anymore to achieve the previous effect. In this case it is a medication of the antidepressant class which is needed for long term treatment of anxiety, so I don't think your late doctor has been doing you any favors by prescribing Xanax.
Last remark, even if you do not agree with me, this site is not the place to get a prescription, it is against the site's policy even if me or any colleague wanted to. So you need to find a good
psychiatrist in order to discuss further treatment.
I hope to have been of help.