Ah, I see. At first I thought it was maybe little things but now you've actually opened up about it to him and he still isn't open and is still secretive then there is a problem.

I'm not telling you to end your relationship, but if I were you I'd be worried about why he's so secretive to the point where he can't even be less secretive with me.

Ultimately it's up to you and what you want to do, you can continue the relationship with the hope that he will open up (perhaps he's opened up more over time?) or it may be that nothing will change and nothing has changed over time either, if that was the case even I would want out.

I'd probably give an ultimatium if I decide to leave the relationship, at the very least tell me why you are so secretive to the point where you can't share anything with me and tell me some basic things that every couple would know or I'm leaving.