Perhaps she meant in bed, rather than in general. loads of girls like their guy to be a bit rough and domineering in the bedroom - it's hot!
Perhaps try thinking of it as role play - you're not going to be an asshole all the time, just when you want to turn her on, right? Ergo, it doesn't mean you ARE an asshole, lol.
Maybe try giving her a few orders when you're making out (my botfirend often starts with a simple 'get on your knees and suck my cock' ), and it really turns me on. perhaps try a few love taps too, try to gaugue if she'd be into a bit of a spanking (important: start gently and warm her up).
I don't know what sexual positions you favour, but she might enjoy something quite submissive, like doggy style?