heroin/drinking

I was out gardening this evening when my husband called me into the house.  Our middle son, J, wanted to talk to us.  It was about T-Man.  Said he heard from some kids he doesn't know very well that our T is hanging out with kids who do heroin.  Some of them are shooting up. He's not sure if T is using or used heroin, but it ain't lookin' good.  J said that he doesn't think T is doing it now because the known "supplier" OD'ed at a concert and, therefore, the kids' connection is out of the picture. J is concerned and makes me wonder if he knows more but is holding back a bit.  Months ago when I tried pumping J for information about T he became very annoyed so I let it go.  Now that J has matured and seemed to be in a very, very good place - he was more willing to share or have wherewithal to let us know.  
Unfortunately, that wasn't the only bad news we got.  J also revealed that he too has a problem - a drinking problem.  First he said he wanted help and then in the same breath --- he said he wants to try and fight it on his own.  His girlfriend encouraged him to talk to us.  I know our son abused drugs and drank and I called him on back in August.  I thought he overreacted when I told we were considering drug testing him.  Ended up letting it go - he went on and blossomed.  I've never seen him so happy.  This really came as a shock, especially now.  
I guess you have to be careful what you wish for -- although MY WISH - wouldn't have really changed the fact that T is using but..... my wish was that my husband would see the urgency that we address this and not ignore it anymore.  I became complacent over time because we weren't "seeing" anything blatant and because I got tired of nagging my husband. I hope he will have the strength to plan and follow through.  Last time was when T stole $600+ from him that he showed any reaction.  Nothing came of it, however.   
Right now I'm just numb.  Numb.