Corporate Work : Not getting enough credit

How do you help someone with the idea that their boss is not giving me enough credit/not promoting me?  So my boss asks me to fix a document and after I have she sends it out to the client with my edits, does not cc me in that email. I am thinking she does not want others to know of my work. She has also not promoted me despite me deserving it. When this happens I start thinking that she is not qualified enough and is less educated than me.

This similar situation has happened many times and I feel deflated and unworthy and upset. In return I start taking more time to answer her emails and taking longer to respond to her and my cold attitude towards her shows in the way I carry myself around her and work related to her. Over the past few years similar situations have happened and I have just learned to live with this feeling.