Why is Subaru such an idiot?

I honestly don't like this show very much. I want to see it to the end, because I'm curious, but seriously. We've already been shown in the show that he's willing to kill himself in order to do things right. So what happens when Rem dies to the white whale, and he gets thrown off the ground-dragon cart? He starts running and screaming "i don't wanna die!" when he KNOWS he'll just come back to life.

So he can't tell them about Return by Death because magic, what a fucking idiotic plot device. Even accepting this, why can't he tell Emilia that there's going to be an attack? No, he starts freaking out and going "WE HAVE TO GO JUST DO WHAT I SAY".

i know I'm not caught up with everyone else, I'm at 17, but seriously, am I just supposed to hate this character that can't properly emotionally or logically function? Ok, now he's just insulting Emilia for NO REASON.

I'll just say it, you guys can enjoy it if you want, and I don't think less of you, but for me, this show is garbage.