Mental Struggle of a Working Mom

I go to a great deal of other blogs for crafting ideas and shopping deals but for those sites that also include articles either by themselves or from readers I'm starting to notice a resounding theme: Well you should have time to do this...
And the 'this' is coming from stay-at-home parents. I'm not saying that stay-at-home parents do absolutely nothing heck during this clean out of the house I found my old chore list with times and days of week that I had when I was a stay-at-home parent and I was doing 8 hours of work on the house every day other than Saturday and Sunday. I used to dedicate 6 hrs a week just in couponing. I'm not saying that stay-at-home parents don't work but I am saying they aren't burdened with the same kind of work. They don't have the demands of those that work around them and then the demands of the household. They don't have to worry about being at their building, seat, or position right on time and work for hours on end for things that don't help the household other than that paycheck once a week or every few weeks depending on your pay schedule.
Now I have been blessed because I do have pretty flexible hours and I only have to work 20 hours a week. But, it is because I am blessed in that manner that the budget, chores, shopping, children and appointments are on my plate. Things are not split up so when a person says, "You should get more sleep" I get annoyed because I would love to get more sleep but then I have to let something else go in my life. I hate it when I hear, "You should exercise more" because I've tried to work it into my schedule and again I have to let things fall.
In the end it comes down to priorities. I always learned that if you want to stay healthy, happy and save money then you need to take care of the things you have. That means trying to keep up with the household which is no easy task. Some people put exercise ahead of the household chores which is fine that is what is best for them. It is the people who do not have a traditional job and then act like the rest of us should have time for spending time with our kids, keeping our house clean, exercising, making home cooked meals every night.... it is those people that have been grating on my nerves.
When I'm at work I think about what I need to do at home and when I'm at home I am consumed with thoughts of work. It's a never ending struggle and I just want to pull my hair out. I just wish people would recognize the struggles of the primary care giver that also works.
Well that was my entire break at work (means I don't get a cigarette which is a good thing because I really need to try and get back to quitting) so back to work with me and I hope I haven't offended too many people.