How long does a guy stay in his cave?

Everything has been going great with my guy. He lives in another state and recently was with me for a week. When he went home he said his company was in shambles. Work that was supposed to be done by his employees was not even started. He said things were in such chaos that he said he would have to cancel the two weeks we were planning on being together in July.
Saturday, a week ago he called and hasn't called since then. He usually calls me daily. I have sent him cute, brief emails and texts and finally decided that since he isn't responding he probably does not want to hear from me right now.
I assume he is just overwhelmed right now and needs space. Is there anything I should do or just wait and if so for how long?
Thanks so much for your advice; I really appreciate it!