when is closure?

I had an opportunity today to sit in Chris' room, alone, for awhile. I cried, of course. I touched his karate belts, which are still on his wall, and it made me sad all over again. I looked at all of his trophies, and some of his clothes. I heard a mention on TV about closure, and it made me wonder. When will I feel it, and what will it feel like? I know that I can't grieve like this forever, but when will it get better?