You didn't mention where you are getting the Methadone from but I am guessing that you are not getting it from a dr. or a clinic as you would have failed your UA's and been detoxed and dropped from the program.
Please listen to what Dave said. You are not taking enough of the Methadone to be helpful. What you are doing now is just chasing your tail. You need to get on a dose of the Methadone that will keep you from needing any other drug to feel like you can function.
Is there the possibility of you going to a Methadone clinic (this is assuming as I said, that you are not at this time ) so you can get properly dosed? If by chance you are going to a clinic you need to get with your councelor and get honest and let them give you the help you need!!!
And as everyone else has said KEEP OFF THE XANAX!! IT is a dangerous, deadly combo you don't want to mess around with. (although if you have been taking the xanax regularly for any length of time it is a good idea to taper down rather than stop cold turkey!!)
[FONT=Georgia][SIZE=4][COLOR=purple][B]"Some days it's not even worth chewing through the restraints!"[/B][/COLOR][/SIZE][/FONT]