The conversation was about details that someone was trying to get out of me. I refused to give them any further details and this is how I explained myself to them: " I am sorry I won't tell you more than this. It's nothing personal. I am not the sharing type."
Does it make any sense, "I am not the sharing type"?
Hmm....the thing is that so far I'm familiar with the expression in the context of jealousy only: I've found out he's stringing along a couple of other girlfriends too, so I'm dumping him - I'm not the sharing type.
Here you are talking about sharing your feelings. I'd say straight out: "I like to keep personal things private."