I am a nice guy, yet girls don't like me! What should I do?

I am good looking, educated, refined and I believe an alpha male in my viewpoint, However, girls always give me the cold shoulder. I have read a lot of stuff about impressing women, but it dosn't seem to work with me! I am really frustrated I am going to be extint as I am 42 and no female is interested in marriage with me, Please help.