What Is The "Norm"?

Nina • Proud mommy

So I know and I am aware not everyone has a significant other who is around to help them with house work, the kids, appointments etc. My question is though, is it normal for it to just be expected you do 100% of everything just because you're a mom? I only ask because my current situation I am working towards getting out of, the father of my kids doesn't ever hardly help. He will do his laundry, make his food, do a few towels and uses them. He is a very selfish man as I am more than aware of. Yes he works, only just started working two new jobs as he never holds down other jobs hes had which has put us in a tight spot. I stay home with the kids, I've been extremely depressed lately and trying to keep up with a house and 3 kids under 4 has become a nightmare. I've gotten a tad lazier then usual and I'm trying to do nightly walks to help give the extra boost I need. He hasn't picked up any household chores, he lets our dishes sit until nasty and then I do them all and be superwoman and clean living room, bed rooms do all the laundry and cook a home cooked meal. My grandma keeps telling me, you're a mom now its your job to do it all. They also believe being a mom means absolutely 100% no free time unless your kids are old enough to babysit themselves, you're supposed to just put on a face and push through even if you want to cry cause that's what normal mom's do, especially single mothers. But look ladies I don't even know what I enjoy anymore, I am mom and that's it there is no deeper underneath anymore because I'm constantly cleaning, meaning to the point there is no relax or play time with my kids because their dad helps with nothing. My son is behind where his learning should be because I have zero moments to do an activity with just him. I just need to know ladies is this what mom's do, because I'm trying to get this mom thing down so I don't get called out or judged or told im a pos. Is this the norm, mom's just take it all on because they're moms?