Hi char, You know I'm pretty much in the shoe's of your H when it comes to reading personal thoughts in a journal. ... and I understand how you were putting these thoughts to pen in order to work thru them in a way so you can find what you are seeking with what you have. I was hoping this is what my W was doing and trying to act "as-if" it is (that is until what I read today, but that has no bearing here.).
... but it is easy to understand how your H is taking it too. It strikes right at the nerve of his insecurities. It makes all his doubts resurface and along with it the pains associated with such doubts. He reacting emotionally right now. These emotions need to be diffuse first. Handling his reactions with compassion and understanding, validating how he feels should help.
I'm truly sorry to hear about this turn of events and I do feel for you...