I think there is a curb. At first we do all we can to.help. Five years later with no changes we are getting fed up, broke, and may be neglecting other loved ones who also need us. Then years later, after being manipulated, lied to, called names and seeing false promises and our adult kids no better, we may decide "no more." There are stages and not all kids steal or call us names we have never expected to ever here from our kids and our belongings and ourselves assaulted, we throw out the playbook and try to survive. True, many of us tell our 20 plus adult kids to live elsewhere and to support themselves bit that is rately our first move.
Does any one way always work for them? No. Tough love straightened my daughter out in a year. Some adult kids take ten or twenty years of being in bad places before they improve no matter what method we use. Some never do.
There is no one method. You have to look at yourself in the mirror every day. If you have had succesd with a different method do share. My daughter respondef to kindness and understanding by taking worse advantage and lying. They are all different.
Where you are now that works for you is all that matters. But our attitudes and methods can change if time stretches on with no results. Hopegully your son will get it together soon!!! We all hope for you.