anyone familiar with xanax?

I am detoxing myself @ home off pain killers. I am on day 2 and to take some of the edge off I was told to take a valium or xanax. The xanax I got is Mylan A4. It has scores like you can cut it into 4's. I have never taken xanax and don't know how much to take in this situation. I can't take too much, I have a 2mo old to take care of. I got hooked when I was perscribed vicodin for pubic dysfunction @ 7mos during my pregnancy. The baby is great, I just want to stop now, and the withdrawls are really overwhelming....so how much should I take of these xanax's. I/4, half...please help