I’m afraid to use hackamore since he is young and even a little wrong movement could hurt him :(
try him bitless. horses react to things they don’t like with a fright, flight, or fight mentality. Your horse is fighting you because he doesn’t like a bit in his mouth. Try him in a hackamore or even just a halter and lead rope
Maybe you could try to do some ground work to initiate codes (vocal orders, actions,...) that will serve you once on his back.
It's important, especially for a young horse, to have these codes, he's probably not understanding what you are asking him to do. If you are sure you gave him the key to assimilate what you want from him, and that he still doesn't listen, that's maybe because he's injured somewhere so you can call your vet, dentist or osteopath to do a check up :)