I have to shake my head in sympathy, and offer a big pincushion of a hug...
It's going to be rough, but you must use this analogy. It's one that has given me a great deal of comfort. When you are in a nightmare, you usually don't know you are. As it intensifies and the fear mounts, it rapidly draws to a conclusion. Then you wake up, and you are disoriented, until you remember what you really are. Then the fear subsides.
He is in the Witness nightmare, and it is starting to draw to a close. Naturally, it is getting more intense and frightening, but eventually he will wake up and remember who he really is. Someday, this will all seem like a bad dream that you only half remember. There will be a period of disorientation, just like when you wake up from a nightmare, but eventually your natural personality will assert itself, and freedom will seem cool and sweet.
Good luck.
CZAR