Weekend fun

Tonight dh came home right after work, which initially thrilled me because I was expecting him to go out tonight and blow us all off. The thing is when he is here, all of our stress levels go through the roof. I understand and agree with him that his company's computer system is stupid and poorly designed. I get that after working out in the cold it's aggravating to have to spend another hour or two fighting with the computer system. I just can't take all the screaming tantrums.
First of all, it was hardly a long day when he didn't even leave the house until about 3:30. Second, everything makes him swear and freak out. I can't help but thing some of this is related to his drinking too. The only time he's not like this is when he's drunk. Right now he's complaining about how much he hates his life, swearing at the stupid Facebook game he plays for "relaxation" and just being loud and obnoxious. I asked him as patiently as I could to just tone it down a little because the kids are sleeping (or at least trying to) and he's yelling obscenities. He snapped at me, as usual , as if I'm just being unreasonable and giving him a hard time for no reason. Then he complained more.
I know his job sucks. I know I probably don't know just how much it does suck. But he doesn't see his part in any of this. His boss told him if he didn't make a certain quota this week he'd take the company car back. He's all pissed because he says he's sick of being threatened with losing the car. He doesn't see that it wouldn't be happening if he did what he was supposed to do. He goes in late, cuts out early to go drinking, and insists that they shouldn't complain because his sales are so good. And that might be true if he worked solely on commission, but he gets a salary too so they expect him to work a certain number of hours, and he doesn't.
If he loses the car, it isn't such a huge inconvenience for him.'he'll just take my car. I will be stuck carless again, plus I'll have to give him gas money again. Which is even more money he can blow on alcohol instead of on what he should be.
I'm so tired of his crap. What am I going to do if (when) he loses this job too?