Gender-biased Discrimination

I am an Executive Director of Marketing at an entertainment company and have been with the company for 2 years.

I am the only woman in the senior management and the company is predominantly male. Since the beginning of my employement, I have had hostile interactions with the male employees of the company and recently, I was told by a male Sr. VP that the reason I was "not liked" was because I was a woman. This was stated twice. I was not liked and had difficulties in my job because I was a strong woman.

It is difficult for me to do my job effectively as I have to deal directly with the men who are hostile. In addition, I have suffered some medical problems (such as heart issues) since I've been with the company.
Also, I am paid nearly 1/2 of what the other male "directors" are paid.

Is this discrimination?

Thank you very much.