BB - how are you this morning? Have read this thread this morning and you remind me so much of me when I had first babe. My DH who is a great husband and dad has also been known to go into a complete rage, it doesn't happen often in fact less and less now, but when it does it is seriously horrible. I think its partly because he's normally so laid back that to see him irrational and raging is such a shock.
Without a doubt the arrival of a baby is a big upheaval to both of you, the impact on your lives will be different for each of you. While you are sleep deprived and still full of hormones it is hard to see that its difficult for him too - everyone is supposed to support the mother, but fathers have a hard time too.
i know you feel your are being protective and only looking out for your baby, but first time mums do tend to be over the top and I was one of the worst - trust me. It's only when you have more children that you wonder why you made such a fuss and I know that I was told this and just thought the person didn't care as much, but it is true.
The 'crimes' your DH committed were a. leaving the baby asleep with the back door wide open and b. shouting and screaming within earshot of the baby. Honestly neither of these are that bad - obviously not ideal, but not as heinous and you feel they are.
i have no experience of AD's, but I wish I had taken them when DD2 was born as I think I had some form of pnd. However If I were you I would talk to DH about how you feel without opportioning any blame use statements like 'I feel' not 'you do'. it doesn't hurt to tell hi that you suspect you may be overreacting, but nonetheless it feels very real to you. i know you feel that he did the shouting, so why should you do the making up, but you need to give him an out. I but you he'll appologise if you meet him half way and not paint him as the evil enemy.
You need to work together as much as possible overr the next few months and years and that means seeing each others point of view. DH and I have evolved over the years nad having three children very close together, we agreed not to ever do competative hard life stories, never to use phrases like 'you never' and to talk when we began to feel resentful. We are one of those vomit making happy couples, but sometimes he still errupts and it makes me feel like crap, so I do know how you feel and promise I'm not getting at you. Good luck.