Alcohol and breastfeeding?

I rarely drink ever but it was a really special occasion this evening and I had a large glass of red wine, my baby is 6 weeks. I had it at 7.30pn and finished it around 9 with a litre of water and a four course meal inbetween..how long after am I able to breastfeed there is conflicting information. I fed my last for 10 months and never drank once, and this was a complete rare occurance and I feel awful.