I am totally on the same page with the whole "detachment" or "little connection" thing. I have said over and over to my AH that I don't feel connected to him right now (or when he was in rehab). I think it is just from getting hurt so much and trying to protect yourself... it is almost like I am numb. I think it is possible to still love your son without liking him very much.
As far as what will happen when he gets out, it will be up to him. Maybe he could live in a halfway house until he can find a place of his own? Does the rehab he is staying at offer options for future living arrangements for their patients? Do they have a work program to help him find a job? These are questions he should be asking. I think that finding a job and a new place to live should be part of HIS recovery.
I think it is totally normal how you are feeling.. just try to take this time for yourself and enjoy the peace while he is away. There is no doubt in my mind that you love your son, but it is ok for you to be angry with him.
Prayer and hugs,
Daisy