Why do I (F) often find myself getting backstabbed by female friends?

I (20 something F) have always been looking for solid, long lasting female friendships since middle school. I didn't have many friends in middle or high school because I wasn't allowed to hang out after school.

However, throughout college when I gained freedom most of my female friends have talked badly behind my back or to my face when I never did anything to them, while my closest friends right now are guys. Is there advice for how to navigate and make friends with women?