Ally, I will be 40 next month and I struggle with the same question. I wish I had an answer for you. But take comfort in knowing you are leaps and bounds ahead of where I was at your age.
I think the only thing you can do is be true to yourself. As others have said if alcohol makes you uncomfortable, YOU can choose to surround yourself with people who don't drink. The advice I give my daughter is only do EXACTLY what YOU want to do. Don't ever let anyone make choices for you by pressuring you or by making you feel "less then" or "different" because of your choices. I'm very impressed by your self awareness and willingness to reach out. So like I said you are WAY ahead of the game.