Hello and Welcome,
I think perhaps it could be you are feeling depressed and anxious about the diabetes and you have been quite ill which may account for the lack of appetite.
I have never heard of Xanax causing weight loss............in fact if anyone discovers a med that causes weight loss, it will be an overnight best seller. :)
Are you able to make yourself eat your meals as ordered by your Dietician? Maybe discussing your likes and dislikes in regards to your food plan would be helpful.
I would love to send you a few pounds for the holidays. I do hope you start getting your appetite back.
Gentle Hugs for you and keep us updated.
Kitt