How much Xanax do you think you would need? http://meds.queensu.ca/~clpsych/orientation/Benzodiazepine%20comparison%20chart.pdf
3mg of Ativan would be about 1.5mg of Xanax. There's not much of a difference... perhaps Xanax makes you feel a little more high, but Ativan will relax your muscles more. Ativan lasts longer, too. I prefer Ativan as the Saint John's Wort I take causes the Xanax to be less effective.
I see you p-doc likes the Neuroleptics too (Seroquel). I'm just coming off it, but it worked well for me (i guess). I liked how Seroquel facilitated sleep and stimulated my appetite. How long have you been on it? You should give it a few weeks, or it was all for naught anyway. I was taking 100mg Pm and 50mg AM at one point... Then again, I'm the type of person who inst easily sedated, anxiety or no, so I had no problem with Zombie mode... Didn't feel much but hunger from it, tbh.
As far as suggestions... Lyrica (Pregabalin) and Neurontin (Gabapentin) are anti-seizure meds that have some effect on GABA like benzos. Kava Kava is not quite a benzo, but it's considered safe in the short term...
Xanax really is quite addictive, and its relatively short half life makes the rebound tough... A lot of MDs refuse to Rx it... I'm sure you can find one that will, but the fact that you are complaining that 3mg of Ativan isn't enough (I take .25mg as needed) would be troublesome to me. What if you find that you need 2 or 3mg of Xanax per day to make you feel right, either?
Maybe you can bargain with the guy: "Switch me to Xanax and I'll only take .75mg per day (3 x .25)"