Welcome to SR Noone. So happy you are here and thank you for sharing your story. There is a lot of hope and healing here. You are not alone. Once you get past the withdrawals, I believe you will see an elevation in your mood. Both Xanax and Heroin are depressants and even though they may make you feel good at the time, the more you take them, the more depressed they will make you.
I think you should talk to a doctor about helping with detox. Coming off opiates is one thing, but the w/d's from benzo's can be life-threatening. You might want to think about going into the ER and just be open and honest with them about your situation. Maybe they would be able to get you into a program to help you with both the addiction and your psych issues as well, not to mention your chronic medical conditions.
Saying prayers for you Noone. Keep us posted.
~Pandie