Hey Belle, I used to have a young TB gelding named Dakota, he was the exact same. but alot worse. I am around many horses in a day as I work 7 days a week at 3 differnt barns training, and cleaning stalls.
You need to get off her face! and I cant beleive you have her jumping when shes like that shes not going to get better by jumping. You need to go back to basics and re-train, get that horse safe on the ground she looks like a horse that retaliates when yelled and screamed at. It dosent help. it dosent train them anything. We as riders are there to train these horses starting from the ground and working your way up to have a well trained quiet and safe horse.
Work on getting her to calm down, shes quite dangerous the way she is and you can tell she is a very bosy mare and insecure. You need to work on her ground manners before you even think about jumping, jumping is to be done when solid ground work and the basics have been layed out and have been learnt.
Why train a horse to jump and then go backwards to your basics to get lead changes. When in my opinion should be done before a horse is jumped. It is way safer and easier on both of you to do the basics everyone does basic training wether they are pros or not we all do our flatwork, and set good foundations for the horse. with out a solid foundation on the flat you have nothing.
I would also wrap her legs, one wrong move and she falls she can really hurt you and herself. Protect yourself and protect your horse.