perspective please

I cried three times today. On my own, in the kitchen, with my back to the kids. Except during the lunchtime nap edition of "Jolly Barnyard", I did have to pause and control my breaking voice. Is this normal? Is it OK that I am regularly crying and feeling completely overwhelmed? Perspective please.

I had a baby thirteen weeks ago.
Baby has not slept through the night, not even close.
I have not slept through the night, not even close.
I am looking after baby and two year old on my own from 7.00am until 5.30pm every day.
I do not have any family here to beg to come and help.
I get everyone out of the house every day for morning activities and afternoon dog walks, rain or shine.
I'm exclusively breast feeding.
Dinner is ready every night before 6.00pm.
The hoover comes out at least once a week.
The dog gets fed.
I talk to friends most days.

I feel like I can't complain. Last time I tried to explain how trapped and sad I feel sometimes, I got, "Well, go back to work then." Way to make me feel better. I need to ask for help more. I need to reach out to people more. I'm turning myself into a pressure cooker that keeps exploding every ten days. We need a babysitter so we can get out and away from the kids. But, I think I need to be a little easier on myself. This is hard.