Communication and sharing

I cried in front of him for the first time yesterday. I hated looking so fucking vulnerable. Felt quite stupid as well. I wasn't even aware where it came from! 
Maybe it was the shock of  knowing his best friend knows stuff from my past. I totally understand why he needed her help and whatever but like shit! I didn't want to tell him in the first place! All I could think about that night I told him was "well it was fun.. now he's gonna break up with me". And now one of the most important people to him knows. I felt kind of shitty and judged. Pressure of having to be perfect felt on me like hundreds of bricks. 
Maybe it's the fact I know he liked the girl once upon a time. So I'm jealous of her... So really stupid! She helped a lot in the all process of us being a couple. She has a boyfriend (kinda) for crying out loud! Still jealous. I think is the fact he respects her so much. He was upset with me 'cause I told him I would tell her that he still smokes. I realise that I should be happy with the fact he is 100% honest with me about that particular matter (and all the rest but that's not the point) he was just really upset with me because of her (in a way but not really.. I'm sure you got the idea) And she is really pretty. Like smocking hot! I would totally have a thing for her if I was a lesbian. How can I compete with that?! 
So yeah.. Maybe it was that. 
Plus all the drama going on at home lately. I wasn't in my best shape to begin with.
And what made me break down crying was the fact he was just staring at me. I just couldn't handle it having him looking at me with a serious and concern stare. A different kind of pressure.
I just can't deal with pressure that well. 
And I hate keep thinking on what caused all the outburst but he wanted to know. How exactly was I supposed to think all this over and tell him?!
"Oh you know... I get a little jealous of your bestie and the fact you share just a personal thing instead of talking to me about it really got under my skin?"  
Ah right! 'Cause I didn't even know that the subject still was a sensible point to him! "I'm over that really" or "No seriously I'm okay with that now!" Well not that okay if he needed to share those fucking things!
And I should just say what's upsetting me when he never does?! Worst, I kept asking if he was okay. Apologizing very time I mention it accidentally and every single time he told me it was okay. Like after the first week or so he was just "no I'm fine" but if she told him to "sort that out once it for all" then he lied.
Maybe that's what really got to me. It's so rare having him telling me why he's upset or mad and actually have him talking about it. She gets to know that stuff and I... Not gonna say I never do but it's so rare. 
He says he is here to help but does he realise I'm here as well? That I want to know every thing about him and help with all the things that put him in a bad mood?