When someone ask for space The answer to "how much time" is "as much as he needs." Don't call him he asked for space, There's a real chance he may never come back, and right now you don't know, and there's nothing that can be done to get him back, or to get an answer. It's an uneasy, lonely, sad place to be in, I know - the kind of sadness you can feel in your stomach. The best move right now is to recognize it's entirely out of your hands, and to take care of yourself. Best of luck.
And today I realized that I am the biggest hypocrite of them all. I tell everyone to keep holding on, that there is light at the end. That everything gets better as long as you continue to wait. I always tell people to have hope. That they need to keep trying because it is too early to give up, that they have so much to live for. Then there is me, and I am barely holding on.