Physical & Emotional Abuse Support Group
Abuse is a general term for the treatment of someone that causes some kind of harm (to the abused person, to the abusers themselves, or to someone else) that is unlawful or wrongful. No one deserves abuse, period. Abuse can be emotional, physical, or sexual.

I wish you as happy a birthday as possible. *have another HUG!!* If you can have something like "a night with the girls," I highly recommend it. Some air, some space, and a way to celebrate something that should be fun.
Sending you wishes for a peaceful birthday.
Hugs and healing thoughts.
Give yourself a good birthday. Treat yourself to lunch or some flowers or a walk in the park. Spend some special time with your son. Don't depend on him, or you might be disappointed.
Happy Happy Birthday to you!!! Enjoy:)
I also agree with telling him to use an alarm next time.
Regarding your post, besides the obvious behavior that you pointed out, if he is taking Xanax regularly and stops cold turkey for this drug test, he is putting himself to some degree through what is called "benzodiazepine withdrawal." It's a very dangerous thing to do for many reasons:
http://www.bcnc.org.uk/symptoms.html
Of particular note:
"Aggressive behaviour, Agitation, Hyperactivity, hysterical or inappropiate laughter, Irrational rage, Irritability, obsessive behaviour"
"Delirium, confusion, psychosis, disorientation, hallucinations (auditory, tactile, visual), Dysphoria (inability to feel pleasure or happiness), Excitability, Paranoia"
People abruptly stopping these medications can also have seizures.
I, too have an H that takes prescribed medications. There have been several times when he decides to quit taking his for various reasons and it's always been a very very ugly situation. I have told him that if he ever stops a particular medication again, I will have no qualms about leaving and going somewhere else. It's not fair to you to have to deal with that on top of everything else.