Boy do I hear you. I have a 4, 2, and 6 months old. We are hardly keeping our heads above water. I just spent an hour putting the baby down and just let the kids watch tv. I shouldn't even be on the computer now, but sesame street was started when I got down, and I just need a break. My house is also torn up a bit from water damage, and we may be spending a few days at my inlaws.
There are a few things we have turned to in desperation. One I hired a mother helper. She is a dear 11 year old, who thanks me for letting her come. My 2 & 4 years old love her. I only pay her 2.50 and hour. She'll come 2 hours twice a week.
I tried Simply Homemade, one of those meal assembly places. For new moms some of them will assemble your meals for free.
Another thing I will do when the house gets back together is get a house keeper to do a once over.
We are generally pretty frugal, so this is different for me. but sayig yes to doing thise things is saying no to the time I could have for other things.
Also think through the projects your hubby is doing at home. Make sure they are really necessary. You need his help right now and if there is anything you can wait on it might be worth it.
As far as disipline, I'm dealing with the same thing. When my oldest girl feels neglected she is so hard to deal with. Disipline almost makes her harder. if I can focus on building our relationship that helps. But life happens, and I can't always do it. We are trying.
brandon has learned to be more gentle, but I still can't trust him. Have you tried a play pen to keep the baby safe when you need to put him/her down.
I better fun, but feel free to write me if you'd like to chat more.