Sorry you have to join us under these circumstances.
Sorry to have to say this, but your son is 18 and is an adult. He has, like so many addicts, violated the decent people around him to maintain his habit. He is doing all the things that addicts do.
As an adult, it is time for him to not live at home and to face all the consequences of his actions. Hiding behind "addiction is a disease" is not any sort of step to help himself. Actions speak more than words. He has to want to stop.. want to lck the disease.. and want a better life. Without those words and those actions the rest means nothing.
He has to do this and he has to want to.
I cannot begin to imagine the heart ache for you. I can certainly understand the anger. Anger is a reasonable reaction to the unreasonable situation of addiction.