There's a lot of assumptions about the future that are all made up in your head? Why can you not decide to have good health and good mental health at the same time? It is about choices. If you want to save your money and buy other stuff like music, you can choose to do that instead of spend the money on liquor.

When you get to college they often have counselling centers; you could decide right now to get a notebook/"texts" from the library and work on making friends/feeling better/getting a future life you would enjoy rather than be anxious, depressed, and self harming. What we imagine about the future is all imagined, in our little pea brains :-) and I have decided when I get anxious that I might as well make myself learn to imagine good things as ugly ones?

The worrying and possible things that could go wrong do not go away anywhere in life, one can only learn to work with them better and adjust one's attitude. I'm 63 and getting older and physically weaker/less able to do stuff and more often in pain, etc. That's not going to get any better? I can worry about that, imagine scenarios of pain or having to have someone else wipe my bottom for me because I'm physically unable or I can adjust my activity and attention to health issues better so it will be a longer time coming or less embarrassing. Just thinking up bad scenarios and giving up doesn't really take a lot of effort or do that much for us but cause pain?

"Decide" you do not want to drink. Buy a silly looking piggy bank and start saving money. Divide your money into payback-what-owed and "music" and what ever else you would like instead of liquor. Decide you don't like liquor and how it makes you feel and remind yourself of that and come up with something else to think/do when you are feeling anxious, depressed, alone, etc.

Think of other things choices besides just your two; two is not a "choice" situation, it's an on/off switch; decide to drink on a schedule/get your neighbor to buy you 1 miniature every 10 days or something instead of whole bottles. Make up some reason that you don't think your parents would mind your seeing a therapist for, tell them you are having trouble concentrating/doing your school work or you have relationship issues and you'd like to see a therapist for 10 sessions (start somewhere) and then use whatever little bit of therapy they are willing to give to make a plan for your future. It can be easier to make a larger plan and work toward that than just to narrowing focus on a single aspect of your life and how it is a problem. The adage about it being easier to steer a car that is moving is true. Do anything toward a direction you would prefer and you should find it easier to move in that direction and forward?