How to quit when you have depression and no support?

I've been actively trying to stop drinking since the beginning of this year, but the longest I've gone is 4 days. I just keep caving because no one around me wants to help me (my parents keep drinking and pushing drinks on me while my friends refuse to see that I have a problem). Even my psychiatrist isn't helping me- she said she was dealing with insurance for my anti-craving medication but its been two weeks and no update. And I'm not even sure anti-craving drugs would work because the root of the problem is that I am so ridiculously depressed- I'm feeling joyless/hopeless/on edge most of the week so that alcohol is my only relief. I have a violent mental breakdown in my car at least once a week in which I plan to off myself. I feel stuck and lonely and full of grief and trauma and maybe this is all the alcohol making me worse, but I can't stop drinking when I already feel so horrific all the time- trying to get through my life without drinking seems impossible. And I know that not drinking won't solve everything because the times I went to the psychward, was ready to off myself, developed anorexia, started putting sharps on my skin,  got massively depressed, had psychotic episodes- that all happened before I started drinking. Drinking or not drinking I am a wreck. Anyone else stuck in a similiar situation?