Is it bad to wash your hair every weekend, if you're black?

I just got highlights in my hair a couple of weeks ago, maybe three weeks ago. Anyway, it's always dry by the end of the week & unmanageable, so I end up washing my hair every weekend, greasing it then curling it. Plus, I'm trying to go natural. So, an I doing anything wrong? Should I stop washing it every weekend? Should I not be curling it daily? Help me please.