I'm not familiar with your entire background. Was there something that you did during your relationship that gave him reason to not trust you? Or is this something about his nature?

I'm going to guess, as you say "the past" that he's just a suspicious person and paranoid. What you did in your past does not count for what you are doing now. Let the past be the past, unless you've actually broken the trust with him in the first place, then it is indeed hard to get over.

Going from that assumption, first off, he does NOT have any rights to your information unless you give it to him. he has no right to be watching your every move. On top of that your going with him on that and letting him be this way is only encouraging him to do so more. Do you think it will end like he promises when you're married? Hell NO. I can promise you, unless he gets help with his paranoia and trust issues, it will continue well into the marriage.