Can anyone help - in the last year or so, my hair has started becoming flat, frizzy AND greasy lucky me, eh. I've always washed it every other day but it's looking like an oil slick now on the second day. It's also ridiculously frizzy as well - like I've been electrocuted. Please help, it used to be thick and lovely! It's wavy, not curly and it's not dyed / highlighted etc.