30 days is a great start and you will feel better each added day.
For me the alcohol and depression are connected, drinking made me depressed and when I was depressed I drank. I've had more sober day than not this year but are still working on staying sober. I've actually started to be happy lately, it really does get better with time.
Keep going, don't give up and don't give in. You can do this, we all can.