How do I handle this?

I have been with someone for nine years, he is all I know because we grew up together (I met him when I was thirteen.) he recently asked for space, it is probably the hardest thing I ever done. He said he just needs space and has no plans of hanging out with anyone else but of course a million things are running through my head. How do I handle this appropriately? How much time do I give him before I realize it’s not worth it anymore (I say this because we broke up a couple months back and are back together and I am exhausted.) and how do I get the thoughts out of my head that he may just want space to explore more options.

Also I wasn’t very clear: we are not broken up, he just says he needs space, so we are not single yet.