Hi Night shop,
Its a terrible situation that is all too common in this Country. I am sorry that You are having to live this way, but here is the simple Truth:
Your Parents are Enabling
Your Brother to live the way that he does. Yes, Your Brother is Responsible for His
Decisions/Behavior. But Your Parents are also responsible for Their
Decisions/Behavior. You cannot help those who will not help themselves. Your Parents have tried. Their deicision to stand by Your Brother--at cost to everyone--is Their
are responsible for it. And, Sadly, Their decision really doesn't give Your Brother any reason to change anything.
Do some research on Codependency, Enabling, Alcoholism/Addictions, Adult Children of Alcoholics, etc--the relationship dynamics are all the same. Look up the "Karpman Drama Triangle" and learn it. Understand how people like Your Brother use it without even knowing, and how people like You and Your Parents are on it--whether You know it or not.
Your Brother is old enough to make Babies, Drive a Car, Kill or be Killed, Vote, Drink Alcohol------and Take Care of Himself.
He needs to be out in the world, so he can learn that 99.9999999999999999% of the people running around don't care at all about him. Then Maybe
he'll begin to Value those who do.