^ good post - won't repeat what cire113 said. Will add that you may want to get a prescription for Indural (propanol), it's a beta blocker that helps tremendously with the high blood pressure, racing heart, and other cardiovascular symptoms. It also helps diminish adrenaline, which is a problem during benzo withdrawal. I took it while going through my benzo withdrawal, and the first year after I quit benzos to help with PAWS. It was an absolute life saver.
You may also want to consider getting some trazodone to have on hand, in case you start getting bad insomnia. The trazodone is an antidepressant, but if you take it at night it helps with sleep. Also, the antidepressant part also helps take the edge off of benzo withdrawal. I took trazodone and 2.5 mgs of melatonin going through withdrawal, and it would knock my ass out if I wasn't in bed when it would kick in. I would literally be stumbling to bed. Imo, trazodone is a pretty forgiving antidepressant to get off of, especially if you're just taking it for sleep issues during withdrawal.
Get an antisiezure med to have on hand, particularly as you lower the dose. You may not need it, but it can literally be a lifesaver if you do need it. Seizures are not fun, and can mess you up pretty good if you're not careful. I had so many grand mal siezures after I quit Xanax I stopped counting them, and quit going to the emergency room for them. I had one driving at night when I first got off Xanax. Didn't know what was going on, but had enough time to pull off the road. Blew chunks all over my windshield, steering wheel, controls, and pissed my pants on cloth seats. As bad as that was, if I didn't have some warning I could have had an accident and killed someone. As gross as that is, I mention it because you may end up having becoming a seizure risk, and you should be aware that they just happen. I never thought about having one while driving until it happened, and I quit driving until the siezures stopped. Waited six months after my last seizure before I got behind the wheel again. Sometimes seizure medication doesn't always work :/
My advice to you regarding your taper schedule is to not rush it. I had no choice but to quit a ten year benzo run cold turkey, and words are inadequate to describe the excruciating mental and physical pain. It lasted about two years. A good taper will prevent a good chunk of that pain and should reduce the amount of time you experience PAWS.. You said you are feeling lousy now, stay on the 6mgs for a few weeks and see if you start feeling better. Once you start feeling better than lower the dose some. I also agree with cire113 about switching to a benzo with a longer half life once you're down to around 2mgs. Be aware that it won't feel as good as Xanax, but it stays in you're system longer so you should feel better physically.
While you are at the 6mgs stage of your taper, now would be a good time to get on a regular sleep schedule and start eating healthy - those two things help withdrawal a lot. I also recommend that you learn some breathing techniques for anxiety and get into the habit of exercising now so when you go lower in your dose you have something to fall back on, especially when you have no energy (ironically exercise helps).
I know some people will disagree with me on this point, but if you have access to medical marijuana when you finally quit benzos, it may help you through some hard times. Marijuana saved me from relapsing on either benzos or booze during my withdrawal and early PAWS time. I haven't had any weed in years (not legal in my state), but I also haven't had a benzo in six years and haven't had a drink in two years, so I considered a valuable tool on my path to sobriety.
I wish you the best of luck in getting off of Xanax. Feel free to hit me up with questions.
). Then he took away 1 mg every week. 
