i agree with arnz. rushing even in a hot horse often comes from a lack of balance to be able to go slower. remember slow takes more muscles and effort than rushing. you mention that your horse goes around with her head in the air which also confirms for me her lack of balance that she is travelling on the fore and not using her back and hind end.
go back to trot work in the basics of the basics - the simplest snaffle bit you can find, be it a mullen, three piece of sorts, or basic snaffle. and to tons of trot with a soft hand until your horse is soft, balanced, and accepting the aids including the bit.
if a horse changes how they go and they need things like martingales, stronger bits, etc. that tells me there is a hole in the basics of their training that needs to be fixed. sure i use a running martingale on my hot TB when we are out hunter pacing and what not for safety reasons, but not because he needs them. i rode him for an hour yest in just a mullen snaffle, no noseband, no martingale, and work through him being strong with lots of trot, give and release on the reins to soften him, half halt with seat and abs, and deep breathing and sinking my weight into my seat and my heels. did he still have some bucking fits? yes but when he settled he was lovely! and i know that as he gets in more work and more shape, he will need less and less amounts of time before he softens and relaxes.
i always ask riders (including myself) why do you use the tack you use? if you take it all away can you still ride your horse? if not, why not? what does that tell you about your riding? what does that tell you about your horse's training? and what can you do to fill in those gaps for a better, more productive ride with better communication between yourself and your horse? (hint: additional tack and/or training gadgets are never the answer) ;)