Sassiness

I just took a deeper look in denessasma's blog and found her description of her DD's sassiness (in april). I thought I read my own blog!
DD is such a strong person, she's got such a strong will and she is testing our boundaries almost every day. And she is 2y and 8m. I find it so hard to keep my authority up and in the last month I more and more often loose my nerves and my temper. I confess, one day i was so angry, I pushed her so she fell on her knees. I am so sorry. She wasn't hurt but she cried and cried and cried. I would so like to be more gentle but mostly I feel so tired.
Ever again she tells me "Leave me alone!" when she is not willing to follow my order. She doesn't open her mouth when I want her to get her teeth brushed. It is a fight every evening! And when we argued she wakes one to two hours after getting to sleep and cries. Sometimes even two or three times a night.
On the other hand she refuses to take a nap after lunch. And she comes all day long and begs for getting books read. It seems as if she doesn't play any longer.
When she started testing her will on my authority and fried told me "This are the terrible twos, they will last until adolescence". Which seems a horror to me.
I can handle some of the stuff with timeouts and consequences as taking the toys away she doesn't pick up and so but what shall I do about her not listening on the streets? When she wants to run free, not taking my hand, and lots of cars on their way? I do not want to have to take the stroller with me all the time because I want her to use her legs and walk. She is old enough for most of the ways (going to the grocery, the post office, the drug store and so on). I tell her that it is dangerous and that' s why she has to take my hand. But it so often ends up in yelling and grabbing her hard by the arm. i do not want that but cannot help it.
Thnak you, goddesses and tiger ladies, for listening.