What to do about my depression?

Hi im 16. I've been depressed for about a year. Heres my story: A year ago I began to notice i was depressed. I've always been a little shy but had friends. All my friends started to smoke weed so I eventually joined in. I really enjoyed it and new that it was given to people who are depressed for medical purposes in California. i smoke up until a couple months ago when my parents found out. Now I am drug tested regularly. I won't be able to smoke or do any other drugs until im 18 a whole year and a half away. Now i am depressed more than ever. Thoughts of loneliness and self loathing walk through my mind like it has a revolving door. I have no dreams or aspirations and am very cynical at the redundancy of life. I am extremely irritable but at least I'm still a monster at black ops. what should I do?