The paint mare I have been riding recently is extremely unbalanced. Until about 6 or 7 months ago she had been a pasture horse and to my knowledge was only green broke (at least that's how she acted when she was dropped off at the barn I ride at). I have been riding her since April or May trying to put some good quality miles on her as she was so unbalanced she could not complete the turn on the short side of the arena at the canter before she ran into the fence. Anyway, I helped her through that, but now I've kind of hit a stand still in her training.
To get her balanced enough to complete an entire lap of the arena I spent a lot of time doing walk-halt-walk, trot-walk-trot, and canter-trot-canter transitions to help her shift some weight off her forehand. The problem I am running into now is that she is still so heavy on the forehand that once she gets moving she starts snowballing faster and faster and is very hard to slow down. She is currently being ridden in a wonder bit on the bottom ring and I feel like I have to physically lift her off the forehand with my hands for her to slow down/stop. It's not that she isn't responding to the bit because it's clear she is when you ask her to back up because it's almost like he panics when you start to pick up the reins to ask her to back (maybe too much gag action? Maybe she can't quite organize her hind end to back?). I have tried riding her on the middle ring of her bit but then she just sticks her nose in the air and goes even more on the forehand.
I'm not really sure where to go with her from here. Are transitions the right thing to keep doing? I feel like I'm holding her back too much, but if I give her any rein she loses all control. She is very responsive to my leg (if your feet touch her sides she rockets forward) and will move off my leg. Any advice would be greatly appreciated.