Husband hates his job

My husband just got a new job, making $2000/ week. It's ALOT of money, he's only 20. However he hates it. He says they call him stupid, yell at him, make him feel like a piece of shit. He says he feels like he's going to get fired every single day.

It worries me because we have a lot of debt we are paying off, I can't work, we have 2 toddlers and one on the way, so we can't afford to lose this. He says he's doing his absolute best and he's going to stick it out but he feels like he will get fired.

I have no idea what to say or do to help him. I love him, but he's not the smartest man, he doesn't understand the simplest tasks, but I know he's trying. I just keep telling him that he should ignore them and do better everyday. But I'm really stressed about him feeling like he will get fired, it's making me feel like we are going to end up homeless! Any advice?