I agree with Kirsty, you need to give more information for others to help you,
for instance if the horse has come of the track it may be detoxing,
If you are giving him feeds that heat him, like oats, then that will only make him flightier.
Do you have control of the horse on the ground, or does the horse have control of you. this means is he pushy, does he respect your space, does he kick when you brush him, or pick up his feet, can you leed him or does he leed you, etc.
You may consider finding someone close to you, who knows about horses to re-educate the horse and teach you how to handle him.