Walk like a girl?

My grandmother got custody of me when i was 12 yrs old. since then (now 23), i have been with her. For years i had got teased even by family for the way i walked. They said most often that i walked like A MAN! straight up and down with my shoulders all the way back, very stiff. Last year after i lost my virginity and the guy stopped talking to me, i made an effort to try to be more feminin, including trying to walk more like a girl. I slouched my shoulders over more and arched my back to the point of being painful at times to make my stick out more. I also added a twist. lately my knee has been killing me and my lower back hurts when i'm up too long. My shoulders are wide for a female, i have big , and a not much . So i figured it would probably look more appealing if i hunched more and twist more, try to imitate other female walks. But more than ever its starting to be uncomfortable. How is a girl supposed to walk? How can i walk more girly with less pain?