The first is cantering. Normally the horse I ride, Charlie, is quite good at cantering and I was today for a bit, but when we changed the lead he suddenly changed. He would do quite a big buck (well, it felt quite big, it probably wasn't huge) and then would go really really fast and not want to slow down. I was getting told to lean back and pull hard on the reins but he ignored it for quite a while and then when he eventually came back to trot he would be going really fast in that as well. Is there nothing I can do when he goes off like that other than sit back and pull on the reins? I got told that my leg was swinging, but it doesn't normally do that so I think it was just because he was going to fast and I was bracing against my stirrups. I found it really difficult to sit into the canter when he was going so fast.
Then when we got onto jumping, he wasn't behaving very well either. The first two times round he avoided the jump by leaping to the side and trotting round it, and then he started dashing around the jump and cantering off. Eventually he went over it and realised that he quite liked it so got really over excited. He trotted round really quickly and when I tried to slow him down he wouldn't really listen. I did sort of slow down, but I could feel him wanting to go fast and if I relaxed he would have gone faster. When he got to near the jump he would rush at it and try to canter really fast over it which was a bit scary because I haven't cantered over a jump before. He did this quite a few times and at one point he went over the jump and cantered off really fast and he was heading towards the fence around the school and I was terrified that he was going to jump over it (he didn't though). I did keep trying though and eventually he calmed down a bit so I could go over the jump properly.
Sorry about the essay, but do you have any advice on how to calm down an over excited horse?