I think an intervention can be done easily with just family members--maybe close friends. I am the mother of an AS 27--who has been sober for over 6 months now--his life sounds simula to your sons. In my opinion as they get older and into their 20s they really take a turn for the worse. I can only tell you that I always supported my AS thru all the melodramas--and by that I mean I was ALWAYS there for him--up/down--I had no control over anything in his life but I wanted him to know--no matter what he did-I was still his Mother---it's alot different when it is your child who is an A...I think--having had an EAH and an AS...I would try to get him into an inpatient treatment center --one that lasts a few months-not 5 days...To help him you may have to hurt him--or you lose them for good.
I too was sure I was going to bury my son--now he is sober....there is always that light at the end of the tunnel....you need to get help for yourself as well--so you can stay strong...feel free to send me a personal PM if you would like to talk about this.....sending you prayers.....