Anyway, it seems like a Camelback might
help when I fall like that.

What do you think?

I'd be worried about popping the Camelbak and leaking whatever you were
drinking all over the place, but if you do tend to fall on your back a lot, try
and drink something that won't stain or be sticky, like water or that flavored
fitness water, rather than regular Gatorade or something, until you know it'll
hold up.

If you have no need for hydration while riding, then I agree with the others
that said buy a Longshot or something similar.