A lifelong lesson in patience, I believe

This mothering thing seems to be a lifelong lesson in patience, no? And I certainly have little of it. However, I do try and try with D. After all, she is just a little baby...
But I have my days. When she is expressing her will to say no and throws her arms around dislodging the food on her spoon and sending it flying onto the floor, I have my days where I just see red and say (very loudly), "No!" "Don't do that!" or "Stop doing that!" And then I feel bad that I've yelled at her because she really doesn't understand and she is really just trying to communicate with me.
And then I have my good days (like today) when she flails her arms around and I just nonchalantly go about feeding her. And she has her fit and starts to cry and I just sit there trying to reason with her or find a diversion. These are they day where I am a bit exasperated that mothering is so difficult (for someone who has zero patience), but I also feel a bit accomplished that I can see beyond my own selfishness of not wanting to clean the floor up and can just to civil to D.
I truly believe that you can teach more by reasoning and not raising the voice, but I fail at that sometimes. I am only human after all.
Do I expect her to be a drone and have no feelings and just be dull every day and do exactly as she's told/shown? Of course not. But it's also hard to know the best formula for combating her unruliness. She needs to eat her food at the given time. I prefer her to eat her main dish as opposed to wanting to eat nothing but sweet potatoes. When she is crying to communicate her disappointment what is the best approach? Removing her from the table until she calms down (but still will start to cry if the food is presented to her)? Or just letting her cry and talking to her? Or...just staring at her blankly when she is crying to indicate to her that her tears and crying are falling on deaf ears? Yeah, that's harsh but it also doesn't work. :o)
And mind you, she looks really, really cute right now when she is crying from frustration. She opens her mouth really wide, lets out a wail and her two little bottom teeth are prominently displayed. Almost like a cartoon baby crying. Really, really cute. I had to let her cry for a bit today just because it was so cute. ;o)