Wow. I can understand how the quality of life can be so unpleasant that anyone would be tempted to do what Oompa did. You did such amazing things for him. I know in time you will understand that you didn't fail him at all, what so ever.
Our mental health system is horribly inadequate. It is tragically inadequate. They failed Oompa, Stacey, you did not.
I'd like to think of you and those who tried to help him, before his final solution and passing to the scene where the character Powder finally leaves a world in which he did not fit:
Forward to 8:01 if you want to just see just the part where he went "...not away, just out: everywhere." ~ Powder