My cat hates everyone but me?

I have a 9month old female kitten who hasn't always been so pleasant. Since the first day I got her she hissed upon coming out of her crate granted I shoulda let her out on her own I hadn't. Since then months go down the road and she now hisses at my boyfriend mainly and runs from him low to the ground like a,rat around my house. She'll hide from him and anyone else even me till she knows it's me. If she hears his voice she Tourette meows and scuttles away n hides.....someone please tell me why shes like this