You need to discuss this with your doctor to see if you need a change in your medication regimen. You could try the Remeron, many people have had success with it, give it a try. There are many good meds out there to help with insomnia, just keep in mind that optimally, anti-insomnia meds should be reserved for short-term use if at all possible.
Hope you get some sleep soon! I think if you do, everything else will improve...your anxiety levels, appetite, etc. Be careful, if you need to go somewhere, it is adviseable to have someone drive you. Your sleep deprivation is severe and could put you in a dangerous position while driving.
Hang in there...and update us if you can!
I read about this all the time and when I do, I then go into my own experiences with this. Anxiety disrupts sleep but when you take drugs to help cure this, those drugs after a while eventually disrupt your brain's chemistry that control your bodily functions, one of which is the sleep/wake cycle. The result is a vicious cycle, anxiety disrupting sleep then the drugs disrupting it more. These meds are not meant for long term.
I can't help you with the remeron, i have never heard of it. However I have the same level of anxiety and insomnia. I take ativan because xanax never helped me. Maybe if xanax isnt taking the edge off, try that?