Horsey situation :) plz give advise x thanx?

Maybe if you have any photos or videos of you jumping previously, show them to your instructor. Or if he lets you, show him you can jump bigger by doing it. Either way just talk to him, and explain what you have explained on here, and tell him you are ready for it and you can do it, at the end of the day you should be allowed to do what you feel your ready for, and instructor is only there to guide you.