Hi Sjbm,
I am so sorry to read your post and can understand how difficult it is to see your son making the choices he is.
If you would like some support for yourself, maybe you would like to contact The Icarus Trust. We are a charity that provides support to people who find themselves in similar situations as yourself, having to deal with a loved one’s addiction. We have a team of experienced people who you could talk with and maybe start to see a way forward as well as finding out what other support is available to you.
You can contact us on help@icarustrust.org or visit the website http://www.icarustrust.org
Good luck.