I do believe it's a failure when you set out to help someone else and end up hurting yourself AND the other person. But it doesn't mean you didn't try or that you didn't care about them.
I think we are coming at this from two different perspectives. Brian did help, Justin did get better and when it got too deep for Brian emotionally he simply was not able to cope. Previously, Justin had been able to push through Brian's barriers, now it is different. Brian and Justin hurt each other, their relationshiop failed, Brian's care of Justin did not fail.