I used to be the exact same way. Paleo diet here too. If your friends are definitely bringing you down, it may just be time to find new friends. Not necessarily write the old ones off, but don't see them and hang around them as much. All my old friends were the same way as you describe yours - didn't care about health, eating right, drugs, drinking, etc. while I was the opposite. I eventually started to meet like-minded people at the gym and at Whole Foods and Trader Joes who cared about health and nutrition as much as I do. I know it can be tough, but just consciously try to not care what they think about you anyway. It took me a while to understand how to do that, but it worked wonders. Just focus on how good you feel because of the way you eat and your lifestyle choices, that's all that matters.
If you can get to where you're truly accepting of yourself and happy with the daily choices you're making, then the opinions of others won't really matter much anymore. In their defense, most people simply don't know a lot of the things that more health-conscious people know. They don't have the facts. And it is definitely frustrating to see those same people who happen to have perfect skin, but there's really nothing anyone can do about that. They've been blessed in a sense. But keep in mind they may feel horrible and sad on the inside without ever really showing it.