I am Standoffish apparently

My manager is completely rude. Period. H.R. is useless. Today My boss was having little "performance chats" with us about selling and everything. She told me that She thinks I don't really try very hard and that she feels i just "get lucky" and people buy stuff. That really hurt my feelings. I do try the best that I can at my job and I know that there's little things I could do to be better but, that is just beyond hurtful....I"m starting to feel like a robot. Then later she told me that I am "stand-offish" was her word... apparently we are 16 and in high school again. Ridiculous. That just is stupid but it really hurt my feelings. I'm kind of stuck and don't know what to do. If I could tell her anything I would say: "I'm sorry I can't be the person that you want me to be, I am happy with who I am and that's all that I can be.. and that's who you hired." But that's the nice version. Sometimes I think she just gives me crappy shifts and glares at me and nit picks EVERYTHING just so I'll leave because she doesn't like me. When i got home tonight I took my dog on a really long walk. It was nice I think i'll start that more often than only walking to work.