For anxiety, try cardiovascular exercise. Works better than benzos for me. I've recently tried low dose of THC in capsules and it did not affect my mood at all (no high either - just absolutely no effect whatsoever). There is no conclusive evidence about potential effects of pot on bipolar - too many confounding factors at play. But at 18, you ought to get serious about exercise. You owe it to yourself. It will help you no matter what drugs your use or do not use. Exercise will also improve your memory - see http://well.blogs.nytimes.com/2012/0...og-the-memory/