First off, there's only something wrong with sleeping around if it bothers you. People give women shit over it because of lingering patriarchal notions dating back from when women were considered little more than cattle. If you want help for your depressive state, though, I'll help you find someone to help you with that.
Sorry. I've been called a slut a few times in my life and it bothers me.
Anyway, if this time feels different, then maybe it is. Right now might be too soon for her to tell, but give it time. She might feel the same way back when the awkwardness wears off.