Exhausted

OK - well I am not sure it makes a lot of sense to do the numbers tally because my income fluctuates greatly. I have two jobs: I work per-diem as a CNA in a rehab/extended living facility, and I wait tables. I work anywhere from 1-3 nights at the facility, and my tips vary greatly depending on what section I am in. So an actual numbers tally is not that representative of the state of our nation.
Instead, I'll write about my perceptions of how things are. Right now, I am so tired I can't see straight and that is usually the case. I am with our twin pre-schoolers all day (they don't actually GO to pre-school because we can't afford it - somehow, incredibly, we make "too much" money to qualify for Head Start), then about four nights a week I go to work, from roughly 3-11 pm. My husband works a regular, full-time job, through which we get our health insurance, and then frequently takes side jobs which he does on weekend days when I'm not working, or weeknights when I'm not working. I also am taking a Spanish class right now because I thought it would be helpful as I continue on a path in health care.
So, in summary, I work about 32-40 hrs a week outside the home. My husband generally works 45-50 weeks. We trade off the twins. Rarely are the four of us together - in fact some days I never see him at all. Those days he leaves for work before we wake up, then I drop the girls at a friends' house for an hour or so when I head to work, he picks them up, and then they're all asleep when I get home from work at night.
Is this normal? Is this how most Americans live now? We do own our home, but it is TINY - really just four rooms: 2 bedrooms, a living room, and an eat-in kitchen. There is also a breezeway we can use as a sitting room about 6 months of the year, and a big yard. I am grateful we own it, don't get me wrong- but it is small. And we were only able to buy it because my grandfather died and left me a small chunk of money we used as a down payment. We do both have late-model vehicles; him a truck, for work, and me a Scion. With children, I feel that I must always have a reliable vehicle, so I guess we have more money tied up on those vehicles than some families might...
but anyway. I am exhausted and my back hurts and I get to do this all over again tomorrow- so more later.