There is a moderate drug interaction between xanax and trazodone. They are both Central Nervous System/Respiratory depressants and taking them together could have a synergistic effect. Therefore, taking the Xanax and Trazodone together in the evening is not recommended unless you have been given clearance by your prescribing physician to do so.
The rest of the medication regimen sounds fine.
If you continue to have difficulty sleeping, you might want to ask for a different medication like Ambien or Seroquel (again, no mixing with the xanax). They can be more effective for sleep if the Trazodone isn't working well enough for you.
I hope this helps, please let me know if you have more questions.