He Always Screws Up

My husband is constantly screwing things up all the time. Much more than the average person. And I just don’t understand it. He’s a very sweet person but he’s constantly screwing up. He has been fired from so many jobs, he has wrecked vehicles, he loses stuff often, breaks stuff often, forgets to pay bills, can never keep track of time and is late to everything, and he got a pistol yesterday and misfired it in our house tonight and scared the hell out of me. I just don’t understand how one person can mess up so much. It stresses me out so badly. I try talking to him about it and he just says he doesn’t know why this stuff always happens. He is constantly down on himself and calls himself a “fuck up”. I feel so bad for him but honestly he kinda is a fuck up. I just don’t know how to help him change... I’m scared he’s going to hurt someone one day. 😬 Is there something underlying that could be causing this? What can I do? I’m so stressed out.