That's replacing one addiction with another. That's not the way to go. Benzos like Xanax are horribly addictive. I'd recommend at most a few days of consecutive use not a whole month.

For withdrawals from the subs look into using loperamide (USA brand name imodium). It is a life saver for opiate withdrawals. It's mainly used for diarrhea but it's an opiod that's too large to cross the blood brain barrier so it doesn't get you high. Just eases 90% of the withdrawals. It is literally a life saver when withdrawals hit. Get a 200ct bottle. Take 20mg. Wait 3 hours. If your withdrawals don't subside take another 5-10mg and wait another 3 hours. Increase until withdrawals subside or you hit around 100mg in a 24 hour period. If you're up to 100mg and the withdrawals aren't subsiding at all do not continue. After you find the dose that works for you take half that dose 12 hours from your last dose. Then every 12 hours for the next 4 days reduce each dose by 2-4mg. So let's say 20mg is your good spot. Take ten milligrams 2x a day. Then the next dose you take 8mg then 6mg the next dose.

Since it's used for diarrhea it's going to block you up a little more than most opiates normally would. I recommend taking Miralax until you're off it or using a glycerin suppository on day two to unblock you. Remember you're doing a quick taper with the loperamide. Do not take it longer than 5 days. You can form a dependency to it as well. The idea is the quick taper weans you off the opiates quickly.

Check out /r/opiates withdrawals survival guide too. You're on day 3 so the worst of the physical withdrawals should be over soon. Might not even need the loperamide at this point.

Taking a couple Xanax here and there when it gets bad is fine. But even taking a bar or two a day will eventually make you dependant.