Good post!! I'm right there with ya! I have 3 kids 8 (9 in Aug.), 5, 3 and prego with #4. I've always been a SAHM too. Lately I'm feeling the same. I'm done. I'm just done. There is no way to keep up with the house, no way! Add my DH works 80 hours a week/6 days and I homeschool. I don't have family here, I don't have close friends and I don't do babysitters! I'm drowning!!! I hate to cook, I hate laundry, I hate to clean! I once read that if you spend all your time doing something you hate you will be miserable. Yes! I love my kids! I love staying home with them and would never trade it. Unfortunately the rest comes along with it. I would love to have a live in nanny/maid to cook and clean for me so I could focus on my kids ALL the time. That is the only solution I have come up with. Well that's not going to happen anytime soon.
I don't have any solutions for you, just to offer I'm in the same boat. It takes me 2-3 days to clean the whole house (this is cleaning most of the day besides to cook). By the time I finish, where I started is already a mess. I wash about 35 loads (maybe less now without diapers, but that will change very soon) a week. It never gets put away. I joke people call us the wrinkle family. If I dedicate the time I should to school work then there is NO time for anything else. Add all the errands, shopping, library, school activities, then things like paying the bills, trying to plan out meals to cook for my super picky kids, oh the cooking and clean up. UGH!!!! I've come a long way though. It seems with each kid I have to let go of more things I do. I have OCD and love an immaculate house. I like to make all our food from scratch. I would love to have the kids in tons of activities. BUT the house is filthy, I buy bread and yogurt and no longer cook elaborate meals. I limit our activities. I've had to do all this just to survive. I don't like it, it drives me crazy, but what else can I do?
I don't know how old your kids are but I've been making my 8 yo take on a lot more responsibly since #4 is on the way. She has to load and unload the dishwasher and hand wash the pots and pans. She can wipe down the table for me. Sometimes put away clothes (if all 9 baskets are full and even more still is coming out of the dryer). I make the other 2 pick up their toys but they just throw everything anywhere. I have bins with pictures of what should be in them...OCD. They are just not old enough/ready for other tasks. I'm sure they could do things their own way (not mine and not right) so I choose not to make them do other tasks. It's too stressful for me.
On the days your feeling like you were in the original post, get out of the house. Do something you like or that makes you happy. Or just try to take the kids somewhere easy for you.