<human>: Can you give me a shortened version of the text?

My bf and I have been together for two years. Before me, he was with a girl for four years and then had about a year in between. She cheated on him once, he forgave her, then she did it again and he finally moved on.

He's never really talked to me about it, all I know is pretty much what I just told you all. But I know it messed him up. I was the first one to say "I love you" because I think he was just paranoid. He doesn't often say cutesy or romantic things, he kind of does the bare minimum. He doesn't talk much about our future. I believe he loves me, and he's a wonderful boyfriend, but I just have this hunch that if I had met him before he was so badly screwed over, he'd be different.

The thought of him being hurt like that makes me incredibly sad, and I can honestly say I would never cheat on him, or anyone for that matter. I've told him this and he says he knows it, but like I said I just think he's still a bit fragile. I know he trusts me, because he doesn't act jealous or snoop on me or anything, but I think he doesn't trust himself, and thinks he can't let himself be as in love and invested in someone again or he'll end up looking stupid.

I completely understand why he'd be like this, or else I wouldn't have made this post. He's even admitted it to me and said he tries to differentiate the two relationships, but not much really changes. I just get a little upset sometimes, and I feel selfish because of it. But I guess I feel like I'm getting "punished" almost for something someone else did to him. I wish I could have had him before he became so cautious and closed-off. 

I guess I'm just looking for some advice on how to better understand this and not take it so personally, or maybe find out if there's something I can be doing to help him more.
<bot>: My bf was hurt by an ex before and still treads lightly in our relationship now because he doesn't want history to repeat itself.