Welcome to MDC, mama. I hope you find lots of good information and support here - it's a good place to be.
and good luck with your dh. My husband isn't a screamer, but he had zero idea what to expect at each developmental stage (i.e., sleeping issues, tantrums, whining, etc.) and he has been completely frustrated at times with no real solutions as to what to do when confronted with very normal behavior from our kids, now ages 3 and 2. I find that lecturing him about behavior really put him on the defensive but when I would offhandedly talk about the normal things that kids do during some of our time together - or discuss how friends with kids the same ages were going through some of the same things, etc., it really helped change his perspective.
When I first returned to work, it was very stressful for me since my dh had never truly been 1:1 with our kids -- he reported yelling at the kids/tantrums and the like -- he has never hit them, and wouldn't, but hearing about how stressful it was really made me question my decision to return to work.
Now, the kids have actually *asked* me to go to work so that they can spend 1:1 time with Daddy, who is apparently Much More Fun Than Mama
-- something I wouldn't have imagined six months ago. It makes me happy, but he had to hear a lot about "normal" or "typical" behaviors from me *and* I had to supply very definite coping strategies and very concrete examples about what a good GD response is. "Hey, it sounds like A was really a terror last night. I've found that when I start bedtime routine stuff around 7pm, he's ready to go by 8 - any longer, and he's too tired to 'behave'. I'm sorry you guys had such a rough time last night!"
It has taken time, but now I think he is the preferred parent some of the time.
Someone has to roughhouse the kids, right?
I don't mean to make light of your situation, and I think all of the previous posters are right - you've gotten good advice here, and only you know whether he is *safe* around your son, etc., or if it is simply situational yelling when he doesn't know how to deal with a certain behavior.