NEED HELP WITH SCARY HORSE!?

So I lease a horse named bijou and she was doing "fine" up until this weekend. So her big problems are weaving back in forth when i'm riding, crow hopping, galloping instead of going into a smooth canter, and lastly, the one that scares me the most, is she sours into the middle and charges at people. doesn't matter how hard i sit deep in the saddle, or if i crop her on the opposite side of her . she has used the tiny circles against me and runs at a gallop and then suddenly turns in those circles on her own in the center and since shes going so fast its hard because at the same time she bucks.....she is sound and nothing is wrong with her..but she ran over two instructors, and a beginer lesson student. I was scared out of my life because i flew off her and hit the gate, and she kept charging and bucking at this little bitty kid....Please help! She was supposed to be trained as a jumper because of her speed but there is no way that i will ever win with her like this! What sort of things such as groundwork ideas, and things to do when she "attacks" people. I have worked with horses who dont stop before or are just fast but nothing like her before...this is a challenge but i want to do it.