One of the side effects of Xanax is insomnia. Is it possible for you to switch around and maybe take it in the morning? You are also going to the gym late and eating very late at night. When I used to work out it gave me a lot of energy and that along with eating so late seems like it would be natural to have trouble winding down. Maybe dinner at the table and more of a night time routine to relax instead of trying to immediately go to sleep. Don't know if this will help at all, but that's my two cents worth.
Goal reached and maintaining since December, 2012.