I Agree Avoidance isnt the answer! However, sometimes those of us closest to the person are not always the best of people to help. It can become very hard to disengage emotionally. It can be very hard to accept that you are just not the person to help someone you care tremendously about. And therein can lie the long haul. Finding the right counsellor, psychologist, CPN or psychiatrist that you can develop a professional working relationship with, most likely with a combination of meds. As someone who has tried various routes with no great success, I know this road well. But I keep trying.
I consider that I am very lucky to still be working and out and about. And with all these situations come unwanted thoughts, sometimes violent. Yes they are common and not just amongst panic and anxiety sufferes. Its the fear that makes those thoughts different for us. Fear gives those thoughts power...the power to terrifiy ourselves, but, in my experince, not to act them out.
I acknowledge the extent of your hurt at being pushed away. It is always a horrible position to be in. You mention your friend has become more open to his diagnosis. That's a good start, as small as it may seem. I believe it is a sign of perspective to some degree returning.
I have also found during my worst periods, that my self absorption just doesnt allow me to hear and listen to those around me. I am fully immersed in my emotional state at the time, and that sensible and logical voice that exists inside my head is quietened.
I was once asked a question... 'Have you hit rock bottom yet or do you have further to fall?' Sometimes it is the case, we do have further to fall before we are at a point where we have had enough and want to change.

I do not pretend to know what the answers are for your friend. we are all different in our experience and recovery. I do believe however, that somewhere inside he has to find a resilience of his own. He has to find his own motivation.

I wish your friend well on his journey, and for you the sincerest of wishes for being a loyal, faithful and caring friend.

Pooh