Partner will NEVER change.

So after my partner promises to change for the good = NO MORE DRINKING and us having a rough week, well me explaining to him that I don’t think I want to try work things out cause I don’t believe he’ll change & him reassuring me this time is ‘different’ he has come home (works all week out of town) smelling like beer, so I ask if his been drinking, without a thought he blurts out no -,- so I ask again he says yes but only one, that his boss made him cos that’s how it is working with business or some shit -,- then continues to say “sorry babe, I only had one, I told my boss you don’t want me drinking so he said just to have one” like wtff. I just feel sick to my stomach knowing that what we’ve been through especially in this last week him begging for another chance (after 6 years of the same bs) he yet again let’s me down. Whether it’s 1 or 25 I don’t give a damn. A promise is a promise, now I think I’m done