If you are own your own horse and are nervous about what the horse is going to do you could see if someone more confident could do it on your horse first so that you can watch and see how your horse goes before getting on and doing it your self I find this really boosts your confidence because once you know your horse can do it it makes you realise that if you just ride your horse how you normally would things will be fine. Hope this helps it's not the best explanation but I hope you get the point as this really works for me.
What my instructor used to do was ask my random questions are I was approaching the jump, I stopped thinking about how big the jump was or scary etc, and instead focused and answering the question! It really helped me relax and stop worrying about jumping!
jamesoconnell my problem is my instructors just tell me to do it its 75cm which i know is small but when i start doing cross country this summer I'm a bit nervous for the hedge
Take it step by step when jumping start off with a pole on the ground and build ur way up