Tina,
Buy what's called Hydrolysed whey protein. Ask them when you go to a protein shop for it.
It is 100% pure protein, and containts 0 carbs and 0 fat. It's like 97% protein. All you gotta do is mix it with water or low fat milk and bob's your uncle.
It's kinda expensive though because it is PURE protein. Nothing else.
I'll recommend HORLEY'S ICE WHEY. It's what I'm taking right now. VP2 tastes the best, although I heard they no longer make it hydrolysed.
But yeah there are lots of cheap proteins out there.
There's a factory on Woodville road, Granville that sell them cheaper than the rest. Vitamin King is a rip off. I recommend you go to the one near me.