Am i a loser? Can i ever stop being one?

I have 2 degrees in biz and econs, and better grades than my gf. I always study much harder than her. But she's smarter. After graduation, she is now earning a much higher pay than me at merrill lynch, and enjoys her work much more than me, i am 2 years older and drawing a pathetic salary at PwC. By the time i hit 30 (5 years from now), she would probably be earning twice as much as me. I never seem to have any luck in anything i do, or i make bad decisions. Why am i such a loser? How can i ever get out of this loser mentality? Or am i destined to remain one? I am just so tired of working twice as hard and getting half as much.