Why do you have to do it alone?
Not to be discouraging - I truly am saying this to help, not to create an obstacle: you can’t do it alone. No one can.
That’s not a bad thing. Everyone who interacts with you already knows you have a problem. Sometimes we think we’ve been hiding it, but anyone who is invested with you (either in a professional or personal way) knows there is a problem. They may not know the details, but they know.
Where there’s a problem, there’s a solution. Getting out of addiction means connecting with people who can listen and guide you on your path. Addiction is a choice that creates habits, and living healthy and grounded (meaning: sober) is also a choice that involves choosing behaviours, habits.
To learn about new choices, healthy choices, we reach out for help (like you did here). That’s a step 
Have a read around here on Talking Sober. TS has so many helpful threads - for example these are some ones I use:
Checking in daily to maintain focus #41
(Checking in is very helpful for keeping connected. In addiction, we isolated - we all isolated ourselves - and to get sober means reaching out of that hole to connect and communicate with other people. Staying connected is important for being healthy and grounded.)
Take care and don’t give up. Take action, keep an open mind, communicate and listen, and take it one day at a time, and you will find your path.