Hi Newly, I`m sorry your having to go through this. I too had a addiction to opiates but alcohol was my main go to.
I don't really have any advice to give you that will help him to agree to seek some help. All you can do is explain to him how it makes you feel, how it`s destroying the relationship (If it hasn`t yet it will in time). That you care about him and that its hard to watch him destroy himself. You could set some boundaries ect but that`s up too you. If his use continues, it will get worse and ultimately you will have to make a very hard decision. It`s next to impossible to force someone into recovery, unless you give him some sort of Ultimatum or they make that decision on there own.
The best suggestion I can give you is seek out a support group for yourself. You need to look after YOU while this is going on. Your health is going to suffer and that`s not good; Now you have 2 sick people trying to survive.
SR is a great place for support and so is Al anon, there may be more in your area.
I wish you both the best