Your baby will be fine! Look at how many mothers used drugs & alcohol during their entire pregnancy and had healthy babies! Stress affects brain development, so quit stressing over something you cant change =))
A lot of people drink and/or do drugs while they're pregnant before they even find out. Try not to stress out about it. I know it's hard but you being stressed out isn't good for the baby either. I had ONE glass of wine with my mom when I was 15 weeks pregnant and she told me that she drank the whole time she was pregnant with all of us (5 kids). Not that she's a good example but please try not to worry. You don't need the stress
Of course I stopped as soon as I found out, but that wasn't until the fifth week and I know the fourth is a critical one in brain and organ development.
If you stopped drinking when you found out you were pregnant I think you should be okay. How far along were you when you found out?