Hi, Thank you for using just answer. I am sure you are aware of most of what I will tell you....
your son is using you and his mother as excuses to continue to use drugs. He is unwilling at this point to take responsibility for his actions, so needs to have a reason to blame it on someone else, just as most drug addicts and alcoholics do. No one has a perfect family life growing up, but once grown, it becomes their responsibility to change what is wrong and create a healthier lifestyle. Please stop blaming yourself for these decisions your son is making.
Your son is stuck in this drug addictive way of thinking, and the only thing that will change that is for him to receive some pain associated with his drug use. Pain comes in many forms and can be things such as not giving him money and not allowing him to stay with you unless he pays, not buying him food, not paying for gas or the car, etc. It can be enforced by you, but could eventually be enforced by the legal system if he doesn't change his behaviors. I know this may be difficult to do, but it is the only thing that can help him see how his behaviors are no longer being tolerated by you and his mother. As long as you provide these things, he will continue to use, because he can.
I hope you don't mind my lack of sugar coating. I have always loved working with drug addicts, and they are some of the best people you will meet, but only once they become clean and sober.
I would also recommend you and your son's mother attend Al Anon, and I am including their website. Please check this out for information and meetings.
Let me know if you have further questions. Gina