I get some pain in my wrists (or forearms near my hands, more accurately) when doing things like straight-bar curls, or straight-bar upright rows.
I've broken one of the bones in my right forearm before, so that could have something to do with it. But I feel it in both sides....
I can't really help you much, only to say that I get it as well. So, you're not alone. I doubt you have broken a bone.
As for bench, it's a different sort of stress on the bone.... the weight is going directly down the length of the bone, as opposed to curls where the bar is perpendicular to the bone.
My only recommendation is to try some different things.... like perhaps use the EZ bar for curls if you haven't tried that already. I find that changing the angle of my grip takes some of the strain away from my wrists/forearms. I hope it helps.