Luis,
WELCOME! Please keep posting here...you will find people who understand and can help and who care. You are a very insightful young man...much wiser than your years. The fact that you are coming to these realizations now, at 18, is wonderful. That means you don't have to wait, like many of us did for 20 or 30 YEARS before getting help and getting sober or clean.
You are taking positive steps in the right direction. Is there perhaps a counselor at your school you could confide in? Depression is a serious thing, and the pot is not going to help that...which I'm sure you know. Just like for me, drinking made my anxiety and depression worse, but that's part of the reason I drank in the first place. Because it made it go away at first!
Stay strong, and keep moving in the right direction for you.
