Doudou
Please take some time to educate yourself concerning alcohol & cocaine addiction. There is a lot of info here on SR & the web in general.
For those non addicts in the relationship confusion is the norm. But there is clarity to be found.
You will find your answers. Whether or not they are the answers you want to hear is a different matter.
In my experience coke use with alcohol is common. Alcohol is a depressant while coke is a stimulant. Also, a sound moral compass typically doesn't go along with that drug use combination.
I hope you find your answers. Your young & have your entire life ahead of you. Trying to live with a drug addict is extremely difficult & can be very dangerous. But I am guessing from your post you already know this & that's why you are here on SR.
It all can be fun & games for a while until one day you wake up & its not that way any longer.