It sounds quite impossible that Marihuana alone would solve all those diverse problems of yours. Therefore let's assume for a moment that it acted as a placebo only. Then, what it gave you is feeling like a big boy. Therefore what you need is not Marihuana or a psychiatrist but the ability to let out the inner man in you. Parents, school, and so on treat 15 year olds as children, but most are no longer. Your mind has matured enough that you want to be treated like an adult. Am I right? If yes, running away and starting an independent life sounds like the best from those options.