WOW! What a combo! An Arab/Stang? Oh dear... you've got yourself a handful... Lol! Anyway, I think I can help 
Not only is he young so he is bound to be stubborn, clumsy, and jumpy. But he is also Arabian/Mustang and they are known for being the two most temperamental/hot horse breeds. AND horses are flight animals, and there is really nothing you can do about that. In time, Red will settle down. But for now you need to either come up with a solution so you aren't scared of him anymore, or you need to find a more experienced, less afraid rider to train him. Horses can sense fear, they're not stupid, Red knows that you are afraid and that makes him even more uneasy and afraid. He doesn't know that you are afraid of HIM, he probably thinks you are afraid of something else that is more likely going to jump out of the bushes and chase him. It is just how horses are (especially young horses, and especially mustangs and arabs).
What I suggest is building trust with him on the ground. Lunge him, do Join Up with him often, graze him, walk him, bathe him, just bond with him. Establish a trust between the two of you. After you feel like he really trusts you and you completely trust him only than can you get back on him. (Keep in mind it may take a lot of time for the two of you to gain each others trust). Lunge him before you get on (this way he won't have as much energy so he won't be as jumpy). Than get on his back and give it a go (but remember you must trust him and not be afraid). If everything goes smoothly then yay! You have yourself a more calm horse... but if you are still afraid of him or if he is still afraid and jumpy then you should probably have someone else ride Red.
Good luck

Not only is he young so he is bound to be stubborn, clumsy, and jumpy. But he is also Arabian/Mustang and they are known for being the two most temperamental/hot horse breeds. AND horses are flight animals, and there is really nothing you can do about that. In time, Red will settle down. But for now you need to either come up with a solution so you aren't scared of him anymore, or you need to find a more experienced, less afraid rider to train him. Horses can sense fear, they're not stupid, Red knows that you are afraid and that makes him even more uneasy and afraid. He doesn't know that you are afraid of HIM, he probably thinks you are afraid of something else that is more likely going to jump out of the bushes and chase him. It is just how horses are (especially young horses, and especially mustangs and arabs).
What I suggest is building trust with him on the ground. Lunge him, do Join Up with him often, graze him, walk him, bathe him, just bond with him. Establish a trust between the two of you. After you feel like he really trusts you and you completely trust him only than can you get back on him. (Keep in mind it may take a lot of time for the two of you to gain each others trust). Lunge him before you get on (this way he won't have as much energy so he won't be as jumpy). Than get on his back and give it a go (but remember you must trust him and not be afraid). If everything goes smoothly then yay! You have yourself a more calm horse... but if you are still afraid of him or if he is still afraid and jumpy then you should probably have someone else ride Red.
Good luck
