I think we have all "been there" in some form or another.
Others have mentioned routines to help. I recommed the FlyLady. www.flylady.net
She suggets routines for cleaning (she calls them zones) and each month is a focus. Decembers focus in on pampering ourselves. Her great motto is "15 minutes at a time". With so many kids its easy to get stressed out and worry about what still needs to be cleaned etc that we often get frustrated easily and forget to enjoy being a parent.
Trust me, I understand that all too well.
I'm nowhere near perfect and still working on "flying" but baby steps make a difference.
When you start to feel your fuse running short, try to seek a quiet place (I know that's easier said then done in a house full of little ones) and just breathe and try to relax. I know with myself its often the little things that get my fuse fired up more than the bigger things. When I feel myself getting hot I try to step away from the situation and take a quick breather and then re-address. Am I perfect at it? Oh no but its in the trying.
Good luck to you and your family. I hope things work out for the best.