At your age I was almost exactly where you are now (without the weed, I gave it up the moment I discovered I was pregnant in my teens). I was 4'11", rocking a solid 350lbs, I took zoloft maybe every three days, drank like a fish and seldom ate. In my mind I was trying to make the hurt stop with my habits.
When I drank I believed the yelling and screaming I endured was manageable, the panic muted. I was resigned to assuming this was all my life would ever be, a cycle of drinking, spousal abuse, panic attacks and staying indoors weeks at a time.
I wish I could tell you I remember those few years I spent floating in the haze and panicked disconnection but honestly aside from a few flashes I remember very little. Time I will never get back.
As the years passed I watched myself fall into self destruction; I watched my husband fall into self destruction, and did nothing. Things changed for me when I was taken by police to stay at a battered women's shelter. I didn't stay but a couple weeks before returning back to my old life but my outlook was changed.
I had spent those two weeks without the Mist (rotgut whiskey), and drying out was tough. I shook and sweated, my heart thudded and I was certain my anxiety and newfound sobriety was going to drive me insane. Nonetheless I returned home, dumped the bottle in the toilet, and started making strides to fixing the things I could control and letting go of the things I couldn't.
Many things happened after that. I started to feel a bit better, less anxious. I lost 120 lbs, I stayed completely away from drinking. Life, or at least the parts I could control were getting better. My husband, however, continued his descent into self destruction. He finally lost his battle in the spring of 2012.
You are precious because you are you. Each day you wake up on the right side of the dirt is a good day. There is no drink or even any medication that can do so much for you, for your fear and sadness, as you can do for yourself.

It starts with loving yourself. Don't feel guilt or shame because you struggle with your anxiety, alcohol, your weight. You are doing what seems to work best for immediate relief. Now is the time to start looking into the future, what is going to make all the craziness your lying brain has concocted to slowly fade away. It doesn't get better quickly but know that how you are feeling right at this moment isn't the way you will always feel. The emotional state is fickle and no feeling is near as permanent as you imagine it to be.
I love me, all 215 lbs of neurotic, heart stent filled mess and all. You should too because even though I don't know you you are awesome, yes all of you, your talents your imperfections, your insecurities...
This is just step one. This is what will give you the will to make the deviation away from self medication. It just takes a single step in the right direction to create an avalanche of healing.