"It's really hard to not drink / smoke weed / etc. when you're in an environment where everyone else does it. " The way to deal with this is change your social circle. If your future depends on it, the change will be worth it. Plenty of young people do not smoke weed or get drunk.

If you read the Hope and Healing thread, you will find that most who struggled to heal finally started healing when they accepted their injury and changed their lifestyle.