Harold, I remembered your thread for some reason and came back to it for advice.
I have a preschooler, toddler and am currenty pg with dc3. Lately I have lost my rag much more than usual - feel so similar to Teela's post above. I hate myself for yelling at dc - my toddler is being very challenging at the moment, raging tantrums every day over everything, and then I scream at preschooler, for not helping me more :(. I had an incident like this today and it has been happening more in the last month. I am so ashamed :(. I do not smack generally, but the temptation has been there so much more often lately and a few times I have snapped and smacked.
Something resonates about being frustrated with dh and this manifesting itself into loss of control with dcs. He is usually quite good at sharing dc and home care, but I think he would happily do less if I let him get away with it. I also need to work on non-martyrdom and not feel awkward about insisting he pulls his weight.
Recently (maybe Christmas, maybe heebie-jeebies about dc3), he has done some things I find really unreasonable - not pulling his weight in different ways. We have had some big rows about it, and This thread made me realize that when I am angry at him because he has dropped me in it (again), that's when I get angry with the dcs because he's inevitably not around and they are. Also (to my shame) when we argue about it, we are both too stubborn to back down and admit wrong (although we might show it in actions).
I don't have a lot to add, but just wanted to let you know that this thread is helping me see my way through this too.
Hope you are feeling better soon x