Depression and anxiety related to marijuana use

You sound very young, even though you still are 18. You sound depressed, but you complain more of fears and anxiety. You rush into things, which is usually designed to reduce anxiety and avoid paying attention to feelings underneath. Using marijuana will help you avoid what you fear as well, but using marijuana will cause its own problems down the road, especially if you have dependent tendencies in your personality (you do sound prone to that from the little narrative you provided).

Cigarettes will divert your attention from problems in the short run, but they will actually increase anxiety and, not to mention, cost a lot these days. All these actions sound like avoidance of overwhelming anxiety, which may or may not be related to underlying Depression. Is there depression or anxiety in your family? Have you had any major stresses in your life? You might want to seek out some professional help to manage your fears first, then start out slowly in the areas that are the most concern.

Who is to say you have to go to college or start a job right away? You seem pressured to make big decisions that will be binding. Most of us change our minds about careers, majors in school, etc. five or ten times over several years. Can you start out with smaller things? For example, attend junior college and live at home for two years. Take your general education courses (which you would have to take at any college anyway) without a lot of pressure or cost, and live in an environment that is familiar (unless your home is full of stress). Take a part-time job, not a full-time one that starts you on a career.

Relationships help, but not when you are too anxious to really enjoy them. Again, you seem pressured to jump in and establish something that is forever. Life is not like that. Most people change relationships as much as career choices and school majors. Things change, so lower your expectations and enjoy more quality with what you have now.