I was on Xanax a couple different times. In the end I was taking 2mg 3x per day. It definitely worked, but it was the duration of effects (3-5 hours) that bothered me. I would wake up in the morning sweating, fiending for another Xanax. That's what made me make the decision to switch to Klonopin 2mg 3x/day for good. It lasts 8-12 hours, and I've never woken up feeling withdrawal symptoms. I've actually forgotten about taking it all day until it was almost time for my third dose, and still no symptoms. I'm not saying Xanax didn't work for me. I'm just saying my body likes Klonopin a lot more, and I get the same anti-anxiety effects from both, so I'm just sticking with the one that doesn't bother me in the mornings. I sleep much better with Klonopin than with Xanax too. I hope you don't experience the morning withdrawals, but if you're taking .5mg 4 times per day (based on your statement of 2mg/day) you should be alright for now. That 4th dose will probably save the withdrawals from ever happening if you time it right.
I didn't have that liberty since I was only getting 3 doses per day. Good luck with the Xanax man. Hope it continues to work well for you.
Peace