partner is an addict....advice please!

[raex]

I know you can't force someone to accept the fact that they are addicted to cocaine, or to admit they have a problem.....but what should you do if they tell you to your face that they don't want to stop, they do it cos they enjoy it and they work hard and deserve it?
I'm talking about my partner. He's 38, has a very well paid but sometimes stressful job, is a fantastic father to our 2 kids and in general is a great guy. However he's been taking cocaine on a regular basis for 12 years or more. By regular i mean now once or twice a week...in the past a lot more. When we first met i used to take with him when we went out, which was very often. Loads of people used to end up at our flat, all taking, and someone would always end up going to buy more in the morning....my partner would usually pay for most of it..
Since i got pregnant with our first child i have stopped taking. Over the last 3 years he has carried on....to a greater or less degree depending on the time. There have been times when he has brought people back to the house whilst i'm having breakfast with the baby, other times he hasn't come home or he has come home but is so out of it that he's been in bed all day and left me to deal with the kids alone etc. etc. Basically, he has admitted that when he goes and takes he completely forgets about everything else....basically the responsibilty he has towards me and the kids. Even if he's said he's just going for a quick beer, he'll come back at 5 in the morning, or he won't come home and his phone will be switched off. He recognises that he lies to me so that he can go out and take without me giving him a hard time. We have talked about it and we decided that he would tell me every time he bought some stuff and every time he takes (not that this is neccesary as you can tell from a mile away!) as his lying about it was becoming a habit. However, that was 4 months ago and we are spiralling down again into the same situation again and it continues to cause problems at home. I suppose the bottom line is that i want him to stop and he wants to carry on. I have questioned my motives for wanting him to stop and he has even made me doubt my stance at times but over the last couple of weeks a few things have happened to make me more resolute than ever....i want cocaine out of my life and out of my house. I want him to see that he's worth more...that he doesn't have to depend on this stuff to be funny or to interact socially with others. I have also noticed that when he takes his face changes completely....much more than it used to.... he gets a kind of sneering look...it's unattractive and disturbing....other people notice but his friends and sister are afraid to tell him (they also take by the way) as he is someone who doesn't like being told what to do. I don't want to leave him, I love him more than anything and I certainly don't want to take his kids away.....but i also don't want to leave things the way they are. I feel like I'm being forced to accept things the way they are or break up my family.....he makes me feel as if i would be breaking up our family for nothing.....aaaaaah! It's so frustrating!
I don't know what i'm asking of you guys here.....any advice or words would be gratefully reeived....feel like i'm dealing with this on my own.