Any use of Xanax is grounding. Further, since its primary use is to combat anxiety disorder, the FAA is going to view any use as a sign of that condition, which is disqualifying in and of itself. Finally, side effects of Xanax include:
depressed mood, thoughts of suicide or hurting yourself, unusual risk-taking behavior, decreased inhibitions, no fear of danger;
For those reasons, I suggest a) don't go near it, and b) contact Dr. Bruce Chien either on the AOPA Forums or at http://aeromedicaldoc.com for further advice.
The medical underwriting part of securing life insurance will also come to a quiet halt. It may not be possible to find life insurance that covers aviation if there is a history of Xanax or recent/present use.
*
I wish it were otherwise as it's a fairly effective and safe product when used properly.
*
Good luck!