SBD - Yes, I've been where you are...my son was only 19 when he broke our rules and was "asked to leave". He had been in rehab and relapsed within a couple of weeks of discharge. He just turned 21, his drug use has escalated and again, he's in rehab. He'll be leaving there in just a few days and he is still not sure about his plan because we are not there to rescue him -- so he is floundering. I love him more than anything. I am very unsure what his future holds, but I am quite sure I won't be enabling him in any way. I love him too much.
I never though parenthood could be so hard. I understand how you are feeling. (((Hugs)))