If you pick up because raising your teenager is hard then you are sending him a louder message than any party he will attend. You will be showing him that when the going gets tough, it's ok to avoid it by drinking. I know that's not the message you want him to hear.
I have triplet boys. They are almost 17. One of them has autism, which comes with it's own set of challenges. Many, many times they have not liked my decisions, but that just too bad. I have a responsibility. I'm sorry if at times they don't like it, but I don't take it personally. You shouldn't either. Hang on and keep doing the right things. Anna is right, it gets better.