You have found the right place Fatima to consider your concerns. My ex partner and the love of my life is a CG, so I may have an idea of where you may be at right now.
I cannot help you with him. Put simply …. if he has this addiction he will need to admit it and to want to help himself. This is something that hopefully he will want to do for himself, because he wants a better life for himself and later , others around him.
It is difficult to know how you should speak to him ? there is not a lot in your post to say how you have tried to speak in the past ?
This addiction knows no boundaries and without knowng what you have already tried, i would say, always be you, always be straight down the line. Be honest with him, and if you can find the right words then deliver them with kindness.
This addiction thinks it is the god of manipulation, It is sad and it is weak, it shouts and screams in an attempt to hide its sadness.
The best way that you can stand with your partner and stand against this addiction is to learn to look after yourself.
I know this may not be the answer that you have come here seeking but it is non the less a truthful one. Looking after you is difficult but is your best and only way of helping him to recover