Your anxiety is understandable.

You could give ur bf a bit longer time and more space. He would get back to you. In the meantime, email or call him from time to time no matter wether he replies, to tell him you do care and worry about him very much, but u want to give him some space.

Honestly, I don't agree with your bf's reaction. He let you worry without any communication. A simply phone call or email saying " honey, i'm ok, but need to be alone" that's all.