I used to get really nervous when going over high jumps and consequently I pressed my legs too hard and my mare always ended up rushing to the jump and it was always a complete disaster. What really helped me to stop getting so nervous, was to stop thinking about the jump, I wouldn't visualize it until I was face to face with it ready to jump it and so I didn't have enough time to be nervous, it really helped me overcome this anxiety and always try to have a challenging higher jump in your practice because then you will start getting used to it and it will make get even more relaxed for competitions! hoped it helped.
Hi Sara, in every nerv wrecking situation it can help If you have visiualized it before. So when you are quiet and relaxed imagin that jump. See it and try to imagine how it feels. See your horse with you riding and doing that jump. Imagine how super powerful you feel when you did it and how proud you wil be. I know it sounds stupid but If you do this several times several days before the real thing your nervs wil be much more in control. Good luck !
Keep jumping the higher you are comfortable with until you and your horse get bored of it, then try a little bigger. In time te massive scary jumps will just seem slightly bigger than the ones you're jumping. Don't rush as you might get a fright then have to go back to very small jumps to get you and your horses confidence back up. Also don't focus on the jump, focus on your job as a rider - the jump is just and obstacle in your way and is only the horses problem, not yours. Ride you turn and line to the jump, keep your rhythm and your position and all will be fine :)
When you what to jump a higher jump I suggest you start at a height that u are comfortable at. When you start to get higher I suggest you do the jump a fyew times until you get comfortable to go higher :)
Hope this helps