Help, my hair is unmanageable, frizzy, and COMPLETELY damaged!?

Well hon, you just worked yourself into a dead end. Cutting it is the only way it's going to grow. Because if you've got as bad split ends as you say, your hair will barely grow. Again, repairing shampoo can't fix a split end either. Once it's split, you just gotta chop it off and start fresh. The fact that you don't use heat protectant spray is an even bigger thing. If it makes your hair greasy, put in some baby powder by the roots to take in that excess oil. Honestly, I use it all the time, and my hair turns out fine. Straightening it that often isn't that bad if you get it trimmed regularly and use a heat protectant spray. But since you don't do either AND use a blowdryer (more heat) you're just trying to kill of your hair. Just get yourself a hair cut, use styling products and work w/ natural hair, or if it's THAT bad, then just relax/rebond your hair. That's basically permanantly straightening it, so you don't have to always apply heat. But seriously, just let your hair air dry if you must.