I think you may be dealing with her just testing you. As far as her being freaky about the whip, and then not caring at all you might want to try this. Depending on if she was ever lunged before, some people don't use a whip (my trainer doesn't really use a whip to much). Next time you're lunging her and she's just walking around not responding, drop the whip and reach towards the ground with your free hand. Sometimes my trainers lesson horses won't go for the whip, but if you bend over and touch your toe they speed right up. Even my horses do it, and they've never really been taught that. Try to talk to her and soothe her when she's acting up and just be consistant. Eventually she'll figure out that galloping and fighting isn't going to get her out of it. Also, if she is being barn sour (which it sounds like) try feeding her like a bucket of grain and such AWAY from the barn. Like in the end of the arena where you work her. Let her know she can still have fun and be safe away from her stall. Do you ever let her loose in the arena by herself? Just so she can run around and kick up her heals and be a horse? Another thing about the whip, instead of cracking it and asking her to go faster than the walk. Just have her walk around and don't ask for anymore at first. All your teaching her right now is to be non-responsive to the whip. Praise her big time whenever she's going good for you, even if it's just walking around. When she's not freaking out or being a spaz love her up! I'm sure you guys will work it out!
Keep us updated on her progess!!!