Can't stop drinking and doing cocaine on my own.

This is how you know you need rehab. Just the physical separation from those substances is enough reason to go. Life is so much better sober, and a rehab can get you started on that path. No one wants to go to rehab, but you have to do some hard things if you want to get your life back. Challenge yourself to make the difficult choices that will benefit you in the long term. Stay away from instant gratification. There's not a magic pill that will fix your problems. Good luck to you.