Hi,
So sorry to read your post that you are struggling to know what to do about your brother and his drug addiction. I work for a charity called Icarus Trust that offers support to people who are dealing with addiction in their family. If you make contact one of our Family Friends would get in touch and talk with you. They are trained and experienced and may help you to know what to do next. They could also let you know what other support is available.
You can contact Icarus Trust on help@icarustrust.org or visit our website http://www.icarustrust.org
Good luck.