I Had One Glass Of Rum (approximately 1/4 Cup) Approximately

I had one glass of rum (approximately 1/4 cup) approximately an hour ago. I am feeling a bit anxious (I'm not a drinker, but do struggle with a bit of anxiety from time to time as I go through the dreaded menopause process.) My doctor prescribed zanex on an as needed basis. I was going to just ride out my anxiety, however it's giving me a but if a headache (probably in combination with the alcohol)... how long should I wait to take a .5mg zanex? Thanks!