Not quite perfect

Over the past couple of weeks I've been struggling with the whole parenting thing. I've been beating myself up over and over and over again for not doing all of the things I had wanted to with my daughter. Mainly bfing. It doesn't make it any easier that one cashier at the local walmart likes to remind me I'm doing her a disservice by purchasing formula for her. Physically I can't breast feed. With both of my children my milk dried up in about two weeks. I tried and tried to boost production for months each time, to no avail. Even friends and family have been pointing out my failed attempts. But most of all I'VE been reminding myself how I've failed my daughter.
My temper hasn't exactly been in check lately either. I've never taken it out on my daughter, but to me it feels as if I'm going against all the peaceful parenting ideals I've been trying to instill into my household. I scream and shout and hit the pillows while my daughter is safely tucked away in her bedroom, but sometimes she hears me venting my frustration. She doesn't nap, she doesn't co-operate with tummy time, in fact she down right refuses to do it, she won't play on her own long enough for me to even toss in a load of laundry, she won't let me put her in her carrier. My lack of down time has been playing a serious role in my temper lately. Single motherhood is no bed of roses. There's no partner there to help when I get frustrated, there's no one there I can depend on to watch her while I try to clean my house, or even help with the cleaning when needed. I am on my own with this not so tiny little Princess who rules over the entire kingdom (aka my life).
But today something made me stop to think. It was those chubby little cheeks with the tiny dimples, and the excited baby squeals eminating from their owner that made me realize, maybe I am doing something right here. Nothing is perfect, nothing has been how I've planned it to be. But somehow I'm doing right by my little girl. She's happy (most of the time, even if it doesn't seem like it), she's amazingly healthy, and she's so strong. My situation is no where near perfect, but it's good enough. I know I should strive for better. But what's the use of beating myself up over the things I haven't accomplished, when there's obviously so much I have?