One safety thing we've learned with one of our geldings who tends to go up when frustrated is to NOT PULL BACK!! Plow rein, keep your hands low and out to the sides, body weight forward and turn him in a circle until he calms down. If you pull back he is more likely to go up and you could pull him over on you. You might have someone help you out by leading him away from the barn, lunging you until he gets used to working away from the barn. Be sure to praise him big time, lots of love and scratches when he is calm and away from the barn. Look up Sylvia Scott's Natural Horsemanship website: Sylvia Scott Natural Horsemanship Training
. She has a question/answer section and has probably addressed this issue before too. She's really good about getting back to you if you email her a question. Goodluck and be safe!!