I am very sorry. This was his choice on a drug affected brain, but it is very common for addicts to go into rehabs and then leave them. Until he wants to get clean.....
RNs son and RN are exceptional. Her brave son cared about his family and wanted their love and support (RN, if I am wrong do correct me). In his case he cared enough about their opinion of him to stay in the program and get clean. Kudos to him and the whole family.
I am in the Nar Anon program (for people who love an addict). They are all over the board (the addicts,) in where their addictions are. There is no way to predict what will be.
Most who have been in NA a few years, like my husband and me) have decided that helping doesn't help. Our loved ones are mostly on their own. Many are homeless, some in cold weather, but they refuse to get help or follow our rules for coming home....although many do short stints at home then leave or get thrown out again. Nar Amon is actually about us, not the addict, and how we can take our lives back. Like we do when we share on this forum, everyone there has a chance to share, if they choose, and we all listen without interrupting. After we are finished we can respond but we are not to judge or tell others what they SHOULD do. We are all in Recovery too from this disease that is a family disease. We find our own way. For me, the 12 Steps and God are my best helpers. There are tons of tools though such as "One day at a time, one hour at a time, sometimes one minute at a time!" What you can't do for your entire life you can often manage for one day or one hour. Easy does it! For each bad thought "How important is it?" If you can't do something right now because we are too frazzled we say "Do the next right thing" even if it is only walking the dog or doing the dishes or calling a friend.
We.Are.Important!!!
I am sorry that your son did not stay. Maybe you can let him do what he will do...he is going to anyways. We have.no control. This saddens me, but I know I can't control Kay.
One thing I learned is that the reason why addicted loved ones often drop out of programs or sleep on park benches rather than shelters is because they rather use their drug of choice than be comfortable. That means they are not in the right mindset to quit. And what can we do? Nothing. Worrying doesn't help them at all. As a worrier, I know.
I hope you can take a walk, read a good book, see your daughter....do things you love to do. Your son is on his own journey making his own decisions. You can choose to try to be happy. In Nar Anon we also tell each other to "fake it till you make it!" You would be amazed at how well this can work. Science has proven that smiling makes you happier for real!!! I tried it and it works
Hugs and love.