Vent all you want, you certainly deserve too. They just don't get it. I totally understand what you are going thru. My AH just started "working" with his using buddy again. (his DOC is also coke and they would do the hotel thing too). He tells me he's not going to use again but he's already drinking again, trying to do it "socially" (I know it CANNOT be done), so I'm sure it's just a matter of time before the drinking leads back to the coke.
Think of it this way....you miss the old person he was before he used. If he's not clean, he's not THAT person anymore. Figure out what you want for YOURSELF and what sort of behavior you will and will not accept from him.
It's hard, because we grieve for the "old" them. Somehow we can see what is coming but their heads are too clouded - it's like they walk around with blinders on or something - they can only see 5 seconds ahead of them and cannot see anything else.
I wish I had some wonderful advice to give you, but I'm still new to all this and going thru the same stuff you are. Just know that you're not alone - someone here will always feel your pain! Good luck and stay strong!