I need some serious relationship advice

So I have a really hard time trusting people, but I do try. And I think I have a good amount of trust in him compared to my trust in others. But sometimes, I feel like he isn't telling me things or he is hiding things from me. So I ask to see if there is something. And when there is, I ask to see what it is. Like any normal person. Usually though, he doesn't want to tell me. So I ask again later. And once he finally tells me, he gets so mad and angry at me. We fight and he tells and screams at me saying it's because I don't trust him. We have had a few fights resort from this. We always talk through it, but it leaves me feeling hurt and upset. I don't know what to do or how to explain this to him that I'm just trying to protect myself. I always feel like I did something wrong when he exploded on me. What should I do?