How to taper off meds - in what order?

You mention an expert is helping you discontinue your cocktail, I believe that would be your Psychiatrist, which is good.
I have been on all the meds you are on but not the antidepressant (Cymbalta). What you are accomplishing is very hard, I personally have discontinued quite a few medications in my life.
I am 54y/o male and suffer from Bipolar Disorder and severe insomnia.
In my experience and after taking in my case many meds I understand what you are going through and empathize with what you are doing and the courage you have undertaken to decide to be drug free, it is a great relief.
In my case, I have, as I shared discontinued meds before but somehow I always end up taking them again, personally my conditions are pretty severe and need to be treated with meds.
With regards to the weight gain (which everyone hates) I do spinning 1 hour a day 6 times a week and eat very healthy so in that area I am ok, but in the past I did gain weight specially with the antipsychotics prescribed to me, Seroquel (quetiapine), Zyprexa (olanzapine) and Abilify (aripiprazole), and a very tough drug, benzodiazepine, Klonopin (clonazepam) in my case.
I did manage to lose the weight which was hard, discontinued gradually the meds as well with the help of my Psychiatrist and I was fine until I had a manic episode and everything came back with a vengeance and had to be hospitalized and be put back on medications.

In my opinion what you are achieving is tough, specially because you have been taking strong and addictive medications (xanax) for some time. My advice to you is to keep going very gradually and do not give up no matter what, but if for some reason you need to be medicated, regretfully you will have to undergo medical treatment with meds if your conditions require so, which by the way you do not mention.

In my opinion the safest way is to be guided by your Dr., keep doing the discontinuation very gradually in order to avoid withdrawals and do not give up.