He won't go foreward!

Definately rule out anything medical, pain, misfit saddle ect. If thats not the case, you need to make him do what your asking. When you give in and then like say ask him to move on, and he doesn't and you just get the attitude of "oh okay, do what you want" he has just won, so you lost. Quarter Horses are usually lazy. If he doesn't buck/rear stay on him if you can and it will be working through his issues. He knows he can win if he throws you. If he's a rearer do a tie down, if he bucks tie his head up so he can't put it down to buck.

Horses, by their very nature, are mostly pretty lazy. When I taught riding, I worked with a horse who would take the riders into the middle of the ring behind my back. Because he was pretty gentle, they put beginners on him, but they couldn't keep him working because they were beginners... It got to the point where I'd have to get on him and make him canter before the rider assigned could get him to do so - and it took me LITERALLY chasing him around the ring with a crop to keep him from trying to park in the middle. But, a year later when I returned to the stable, the horse was no longer being ridden by beginners and he was no longer considered a gentle, but problem horse, they now put "intermediate" riders on him and he was considered "a challenge." I think you are going to have to work with this horse until he understand that YOU are the boss, not him and at least for the time, put up with, and retrain him from this behavior.

I am presuming you ave made the normal checks for lameness, had the dentist and sadle fitter out? See how he behaves with other riders. No joy? then back to school for him and lunge him all the best urban